Switched from 8320 to 9700 a week ago, still with T-mobile. I strongly considered Android as I'm a heavy user of Google services but went with the 9700 as I got to keep my grandfathered Blackberry data plan pricing of $20/month, and get to do tethering.
I just posted a long review on the 9700 (with many comments on use of Google services) at AMZN, here:
Amazon.com: Customer Reviews: BlackBerry Bold 9700 Phone (T-Mobile)
Since this is just a "First Impressions" thread, I'll just include my summary:
The Blackberry 9700 with T-mobile is a great phone and communication device that is also a pretty good pocket computer, all in an attractive, easy to hold and use form factor - all at a very reasonable monthly plan cost for the heavy phone and data user. It is a huge improvement over the 83xx series in almost every respect. The only significant disadvantages compared with other smartphones are a barely usable browser, a cumbersome setup for third-party apps, and the general complication of customizing the device. For those who value a browser and ease of use above all and are willing to pay for it, the iPhone is better - but for those who want a great smartphone on a budget - this is a great choice. 5 stars.