It's not bad at all, the main issue I can see right now is that it's a bit underpowered compared to most fanfic robots ;P A while ago I did a table that shows the relative power and weight of several commonly used fanfic motors, feel free to look in there and choose something suitable. For reference, a lot of fanfic heavyweights use either the A28-400 Mags at 24v or the 36v LEM130s and have speeds between 12-20mph.