Welcome aboard! I like the 8100.
But it depends what you going to use it for and what you need. If you more into business type phone than 8700 might be better for you. There's also going to be a 8800 coming soon that will do everything that 8100 can do plus more. It also have a full size keyboard like the 8700.
If you are interested, I made a chart comparing the Sidekick 3 vs Blackberry 8100. It's available here: http://www.geocities.com/sk3vsbb8100/