So I had first impressions with this at a shop (if they had the best configuration I might've got it, need something ultraportable asap as I needed stuff last year but there was nothing I liked around and I don't want to pay $$$$ for something with issues that can be seen within 15 minutes of testing as that just spells theres likely more issues that flew past QA):
1. Feel of keys may be acceptable for light use except...
2. The spacebar doesn't feel the same as the rest of the keys (tried various colors of the cheapest model). It seems to require less force to press down. The concerns here are: is it too easy to accidentally press and whether the longevity is good (already found a report of some sort of issue with the spacebar)
3. The only usb type-c was quite tight to pull out but atleast it was decently easy to plug back in. I'd definitely prefer some way of having that magnetic power connector there too and ability to choose whether you want 2 type-c ports of 1 + 3.5" jack... (I'd rather have the audio stuff in a type-c usb dongle with 3.5" in+out, type-c and wireless audio in one dongle)
I'd sacrifice some slimness for more ports - couple more ports shouldn't add much weight if everything else stays same.
edit: You could put the magsafe connector in the power adapter end. I didn't notice if they had done this
4. The factory configuration option of 1.3 Ghz (->2.9 Ghz) also has vPro and TSX. So if you happen to use something in future that would benefit of TSX, you could be missing out possibly noticeable gains by going with cheaper model.
5. It's likely these broadwell models won't be around that long and Skylake could have a bit more single threaded x86 perf at same frequency.
6. The screen opens with one hand and the angle is just wide enough (wider than Zenbook ux305)
7. Viewing angles are good enough for single user though nowhere near my 15" oled tv nevermind a CRT. I didn't have a chance to view it in dark room. I haven't really liked any of the Apple displays in past - this could be best so far in this size but I would need more time to determine that.
8. Pad mouse pointer lags bit less that typical portable PC's but it still lags. Acer laptops don't have noticeable pointer lag. Just barely within acceptable I'd say.
It's pretty serious kit for its weight as that includes the keyboard and the power adapter looked very light tiny and lightweight too. There's probably more competition coming to this space "soon" but if I want soon to be "now" then this is very high on the list. Shame about the spacebar, that is really my biggest concern here from this 15 minutes of trying it.