I go with Powersupport anti-glare on everything. I order direct, get them within days (iPad 2 still not available yet though).
They go on very easy, you can reposition them many times while trying to get them installed and as long as there's no dust, the end result is perfect. The surface ends up being very smooth, not remotely sticky or rubbery. I really does make fast finger movements easier (like with air hockey and such).
They do affect the screen appearance slightly, and I suspect some would not like that. It's probably a matter of opinion, as I don't mind it at all. It's offering anti-glare capabilities and I use my iPad in a variety of lighting conditions, so cutting the glare is a priority and the screen still looks great to me.
But if a crystal clear, totally unadulterated display is your number one priority, the anti-glare won't make you happy. I do have one device with the Powersupport crystal film, my old iphone 3, and it looks great, but just as shiny as an unprotected screen. The phones been through a lot, the film looks great, i imagine the screen behind it is still perfect. So both types offer great protection in my experience. That's why I'll happily wait until Powersupport ships an IPad 2 version.