I used that Rovio bot in a robotics class. I'm no robotics expert (hardly a novice), but this was my experience.
The big hold-up is lack of access to (or maybe pure lack of) encoders on the wheels (we were using the wifi/web interface). It's impossible to move by dead reckoning. This was actually part of our class, to teach us how bad dead reckoning is and then we moved on to CV for tracking and control.
1. Looks like it's been out for a while. If you were getting a similar thing today, would you stick with it or go for something else [1]?
2. When you drop the beaglebone into the Rovio, would you actually be replacing its OEM controller, or just interacting with it over WiFi?
[1] http://www.amazon.com/Rover-App-Controlled-Tank-Night-Vision...