With how thick and wide the base is, and the amount of water used for the perc system, the Rattle can is as stable as a tank. I just gave my rig some solid punches to the mouthpiece and can area and all it did was slide along my desk, no wobbling/fear of tipping. Also, with my Liger v3 20mm (which is quite heavy) I have the bucket oriented directly over the can so it is very ergonomic and adds to the stability.
Edit: Also, I prefer the versatility of the 18mm female joint on the Rattle can to the 14mm male joint on the FC-710.
Edit2: I also seem to remember hearing that the glass is rather thin of the FC-710. Definitely not an issue on my Rattle can