I think they broke the launcher system in 2.1 somehow. No matter what launcher I've used since the 2.1 update, I've had issues with my home screen taking a while to load all of my icons if I've had an app open for a min or two and then go back to my home screen. A couple of times it took literally 40 secs or so (I counted) for it to start loading all my icons. I thought I was going to have to do a battery pull cuz it was so unresponsive while it was loading.
Right now I'm using the newest NexBeast ROM with the ADW launcher and while it's still a little laggy loading my home screen occasionally, it seems to be a bit faster than the default 2.1 launcher I was using before. It's also pretty nice having a 2.2 style launcher with additional icons at the bottom of the screen too.