Only just updated to IE7 in one of my systems. It was might fast in comparison to Fx 2.0.0.1 and 2.0.0.4 builds, so I started troubleshooting and it came down to Auto scrolling/Smooth scrolling adding a good 6-11 seconds to the total webpage load time.
Obviously forums such as this (or Castlecorp) with tables experiencing the biggest issue.
Even with those settings chosen though, Gran Paradiso A5 is quicker, around 3-4 seconds quicker per page. So far I've not experienced any issues with it - the ones I've encountered are typically CSS/JS site dependent, bad source coding.