Upgrading my Sprint Hero to 2.1 has been a complete disaster. The one improvement is that the browsers work faster. Oh...and the menus are prettier and perhaps more intuitive. The phone and just about every other function hangs, the phone locks up constantly - especially when entering and leaving email - and generally is unusable. I've been doing battery pulls 4+ times a day just to get the phone re-started when it locks up. I work for a university and they got me a warranty replacement, which I've had for all of 8 hours. I can already tell that it's not as responsive as the previous Hero before I "upgraded" it. I'm just hoping it won't be as consistently laggy and non-responsive as the upgraded one. My advice to anyone reading this thread - if your phone has not been upgraded to OS 2.1, DO NOT DO IT. Wait until a couple more updates are available...my experience has been completely bad. Right now I can't wait for another update, hoping that it will resolve all the lag and hangup problems created by 2.1. From scanning this forum, it doesn't appear that this has been the case for everyone, which is good - I'd hate to see everyone having the problems I am.