I have tried in store demos, phones both cheap and expensive, tablets both odd brand and expensive high end brands. They can't keep up with my 90wpm typing. Apps force close a lot, device gets hot, apps acting weird, working the third try. False no Internet errors...self rebooting. Having to reboot forcibly because its acting too slow to be usable. Or locks up when not being used at all. I have to post to AF on an ipad because it takes twice the time to type on android.
I'm a bit upset at times. The choppy screen transitions, present on all android devices (I found out why, because android doesn't give all priority to the UI or queue tasks the way IOS does) bugs the living daylight out of me.
No Linux based operating system should need a reboot. EVER. These systems run mainframes for crying out loud.
As for lag, this:
There HAS to be a way to force UI rendering as top priority. Quite frankly I am not sure why its not done. If one thing continues to bug me, its Android lag.