So, I've discovered that even on my t935 (after having bought and returned a Yoga followed by the SP4 ) Adobe Illustrator doesn't work properly. The digitizer seems have to have a lot of difficulty registering my pen strokes when using the pen tool (and stylus, of course). I had the exact same problem with those previous 2 computers too. Now I feel kinda bad for returning those other computers for the same reason. I thought maybe it the high resolution and Illustrator doesn't really allow for enlarging its anchor points (something Adobe really needs to fix) so I tried to lower the res by half. It didn't work. Now, I'm back on my t901 because AI works just fine on it. Any ideas out there why this might be the case? Thanks!