I have Opera Mobile 8.65 and it is an excellent browser. I bought it because of the information supplied by Menneisyys, who writes extremely thorough reviews here. His overview of browsers is something you might wish to explore:
http://www.mobilitysite.com/boards/a...e-roundup.html
I could be wrong about the compatibility of Mobile shell with earlier Windows Mobile operating systems. Still, the changes from one operating system to the next in windows mobile have been significant enough that it would be worth checking carefully before making a purchase.
Glad you're here, by the way--Welcome to the site and ask questions any time!