It's fine on Pinterest. If you scroll as a fast as possible the screen goes white and then loads, but why would you scroll that fast anyway? In normal use it's perfect. In fact, I had Tweetro running on the side, plus Outlook 2013, Board Express, and Kindle running in the background while testing Pinterest. For most apps, and all win 8/metro apps, its great.
The only performance problems I've had are with games. Angry Birds is fine. Hydro Thunder, not good.
I'm not sure if it's fair, but I ran Riptide on a Surface RT, iPad Mini, and ThinkPad T2 side by side. What an eye opener. The two win8 machines weren't even close. Like I said, that's not a fair comparison, but interesting nonetheless.
Sent from my Windows 8 device using Board Express Pro