I regularly use SD Cards, probably more so than USB ports, so not having an onboard SD Card reader means using a dongle USB-C to SD Reader adapter.  I picked one up for $10 on Amazon which works fine, but it’s one more thing to carry around and lose and I’m sure it’s one of those things that is never handy when you actually need it.
I’m ok with only a single USB port for 90% of the time, but that 10% of the time I need to 2 or more the single USB 3 port will be an issue.    I sometimes use my laptop for music recording or editing with Pro Tools, which requires at least 3 USB ports (1 for external hard drive, 1 for Audio interface, 1 for iLok.  I bought the Antopm Multiport adapter from amazon for around $50. It’s very small & light and has any port I may need.  So far it works great and it’s small enough to leave in the case.  http://amzn.to/2j5g0Ad
I understand we can’t have both an ultra-slim 3lb laptop and load it with every port.  I prefer the lightweight and portability, so I’m ok with needing the multiport adapter.  The SD Reader is the only thing I wish they were able to squeeze in.

I believe this isn’t a Yoga specific issue, rather a Windows/Adobe issue.  Due to the high resolution screen and the zoom scaling going on there is an issue in some applications, including all the Adobe CC apps, where the directory browsing icons are tiny and barely usable.  Titlebars are also very small.  The Adobe apps in general all have small menus, toolbars, and titlebars.  They perform great, but be ready for micro fonts and icons.  I’m really hoping they add a feature to all the Adobe applications to increase the size of the toolbar icons and menu/title fonts.   There no chance you’d be able to use these on a touchscreen with your finger.

Directory browsing icons are very small in some Adobe CC applications.

ProDPI Ordering app is tiny and unusable with the 4k display and out of the box settings.

I’m neutral on the battery life.  It seems highly variable depending on the use.  For the first couple of days it was working hard downloading about 500GB of One Drive data, downloading & installing Adobe CC apps, and syncing up my inbox.  During this time it was only getting 2 or 3 hours, and the base was running very hot.
After things settled in though the battery life gets around 8 hours for light use of email & web browsing with some misc tasks thrown in there.
It’s significantly better than my last laptop and should be plenty for my needs.  I haven’t had a comparable model to compare it to and I don’t really trust the published numbers.
For now, I’d say I average about 6 hours and I keep the screen pretty dim.  Brighter screen would probably be significantly less.
UPDATE 12/18/17:  I do still find myself looking for a plug a bit more than I was hoping and it seems to be draining the battery while in sleep mode more than I would expect.  At night when I’m done, I just close the lid and unplug the charger if it’s already near or at full charge, and when I resume the next day it’s around 70%.    It also gets pretty hot at the base while charging, so I tend to unplug it while I’m working on it if it’s actually on my lap.

For the most part the heat isn’t an issue, but at times the base gets very hot.  It’s kind of to be expected with high performance ultra books.
It seems the hottest when plugged in an charging a low battery while also actively working.

The USB-C charger might be better as a right angle, even better would be magnetic.   I’ve lost a couple laptops in the past from the charger jack breaking due to either tripping on the cord or pressure against the plug.  The Yoga 920 charger sticks out to the side when plugged in and doesn’t feel very sturdy.  With everything else about this laptop being designed with great though & care, it would have been a nice touch to have a durable and unobtrusive input jack.
Also note the charger input jack is on the left side.  I’m used to it being on the right, and for some reason almost every time I need to plug it in the outlet is on the right side so the cable has to wrap around the back.  I suppose it doesn’t matter and should be 50/50, but personally I prefer it on the right.

The USB-C charger might be better as a right angle, even better would be magnetic.   I’ve lost a couple laptops in the past from the charger jack breaking due to either tripping on the cord or pressure against the plug.  The Yoga 920 charger sticks out to the side when plugged in and doesn’t feel very sturdy.  With everything else about this laptop being designed with great though & care, it would have been a nice touch to have a durable and unobtrusive input jack.
Also note the charger input jack is on the left side.  I’m used to it being on the right, and for some reason almost every time I need to plug it in the outlet is on the right side so the cable has to wrap around the back.  I suppose it doesn’t matter and should be 50/50, but personally I prefer it on the right.

I’ve dealt with Lenovo’s support department a few times so far.

1. Return a duplicate canceled order that had shipped.
   1. 1st attempt, rep set up the return and said everything should be all set. I waited for about a week without any sort of email or call with instructions on the return.
   2. 2nd attempt, I explained and when they looked into it had found that the return had been denied for some reason and there was zero attempt to inform me of that.  The rep started a new return, which worked out fine in the end.  They supplied a return shipping label and provided a full refund.  (NOTE:  Lenovo has a 15% restock fee on returns unless it’s their fault.  There isn’t even a 30-day customer satisfaction window.  This alone almost prevented me from ordering direct from Lenovo, but it wasn’t available at BestBuy or retail stores yet.)
2. Contact tech support another time to try to find out what the 2 small coin batteries are for that came with it.  They seemed to go with the active pen, but the main battery compartment is for a AAA.   After waiting for about 10 minutes I was connected with a rep.  Then waited another 5 minutes for them to respond.  Then had to answer all sorts of questions, SN, address, phone, email, order #, etc.  That took another 5 minutes.   Then I was able to ask my question again about the batteries.  A couple minutes later I got a response, “please hold while I research our technical documents” or something along those lines.  I waited for a while. After about 30 minutes, they just disconnected the chat.
   1. Note:  I asked the question on the Active Pen product page on Amazon and someone replied with nice detailed instructions on where they go.  (hint: it’s in a secret compartment in the top section of the pen.)
3. My order was done through the sales chat.  It was actually a decent experience, however I wanted the darker greyish originally and when I asked about it and reference the photo showing the 3 colors, he said it wasn’t available and they aren’t sure if they are going to make it.  I thought this was odd, and we went ahead with the silver.  Then after looking into it more, saw that the Bronze is the darker color and is certainly available and for sale.  So I reordered the bronze later that day and canceled the silver.  For anyone interested, the Bronze is really more of a Charcoal grey than what you might consider bronze.  It’s a great color.

These aren’t major issues, but my concern is that should a real issue arise I have little confidence in getting it resolved efficiently through Lenovo. Hopefully the day will never come, but solid customer service is very important to me.  I’ve had my share of computer hardware issues over the years.  Some manufacturers handle it well.  Others not so much.
I used to be a frequent HP customer, but have given up on them for continuous horrendous support.  Both their inability to troubleshoot and resolve issues, and the lack of hardware support (firmware, driver updates) on computers that may be a couple years old.