I've been generally happy with the price and hardware, but I've grown to really hate Arduino. Makeblock publishes a bunch of code, but it's highly redundant and poorly organized, and I find myself constantly using the slightly wrong version of different pieces of code. But IF I ever figure this stuff out, I'm slightly hopeful about controlling the Makeblock hardware from RaspberryPi.
The basic approach is to have the RPI connected to the Arduino board via a serial connection (this has also difficult to setup, but sometimes I can do serial over the USB), and then there's just a very simple protocol that runs. Once this is actually working properly, there's a fairly small Python library to do the talking, and you get the benefit of the RPI environment (logins, wifi, camera access, etc), but with the hardware of the Makeblock unit (on-board sensors, no direct GPIO handling or contention, and pluggable sensors and motors). But getting there... ugh, it's been really challenging and I only got hints of it really working so far.