I haven't rooted any of them. Most have had similar issues, but not always exactly the same. They have all been dog slow. The last one kept dropping my bluetooth connection for instance, but this current one isn't.
I don't have a ton of apps installed. And any apps I have are well known apps (foursquare, astro, layer, movies, etc.). Besides, I noticed right away when I first got the phone it wasn't the quickest. This most recent one was giving me the force close, wait, report pop ups almost right away! Even before I added apps.