The HTML5 UI looks a little crisper I guess, but there are a couple of small usability issues we've noticed. When clocking in/out, the time is no longer highlighted automatically, so we have to fist highlight it, then change it.
There is also no "Save & New" or "Save & Copy" from the punch window, as there is with the old UI.
Not big items, but slightly annoying, and used a number of times every day.
HTML5 UI Notes (Community Edition)
Re: HTML5 UI Notes (Community Edition)
The issues you mentioned have been escalated to the development team for review.