I'd be cautious: the range is too small for me (6'1" / 188cm). On a regular desk that suits me, it doesn't go high enough, and if you prop things on the desks up a bit, you then need to remove them when you lower it.
(It's also a bit wobbly, which isn't great, but probably expected.)
Performance is one of the things we think we're doing really well with Kendo UI. We're jsPerfing everything we put in Kendo UI to make sure it's as fast as possible.
Ultimately, impact on page performance largely depends on how you use the tools (same goes for .NET). Used correctly, Kendo UI will help you deliver maximum perf for rich UI.
Thanks! I'll share this feedback with the team. FWIW, we work very hard to "play well with others". For example, there's an example of Kendo UI integration with Knockout here:
Older versions of Firefox, Internet Explorer, and Safari are supported. Can you elaborate on the phrase, "only properly supporting WebKit"?
EDIT: Got it. Yes, you're correct; currently, Kendo UI Mobile provides UI widgets that match the theming and functionality of native controls available for iOS and Android.