the 250 will be alot easier to ride,you can evan plod about on them if your just messing about,but with the 125 you have always got to be in the power band and to me it gets boreing,next time you see a 125 blasting round the track, cover your ears and the thing will look like its going backwrds.....lol
anyway just borrow your m8s,your soon pick it up,and at least when you bin it your on grass.......