I switched from the Blackberry 8900 on T-Mo's network. So for me, I took several huge steps with this move.
1. EDGE (2G) to 3/4G
2. Much larger device with a higher screen resolution to include touch screen
3. No more annoying trackball
4. Much better operating system (and I was running 5.0)
5. Much more apps
6. MUCH BETTER BROWSER EXPERIENCE (yes, I'm yelling this one)
7. A kickstand
8. HTC Sense UI
The only things I wish the EVO had that my 8900 provided are-
1. I had several friends with BB's and BBM was our choice form of connection. I'll get over this.
2. Native customizable settings for device profiles and apps (I.E. setting the length of vibrations for email, sms, phone calls, etc.). I've been playing around with several different apps, but nothing gets close to my 8900 options.
It took me several hours to get use to an Android OS, but I think I got it now. Also, I highly suggest installing a 3rd party keyboard like Swype or SharpWriter...which, I use the latter. This will make the change from a physical keyboard seamless...I mean, I think I can crank out messages faster then I could on my 8900...for real.
Battery life...I had great battery life with my 8900, this has yet to be determined on my EVO...ymmv on this.
All in all, it was well worth the switch. I just hope RIM will get off their laurels and catch up before it's too late.