A properly jetted 250f won't bog like a 2t. It will build power slower if you're in too high of a gear. The clutch does work the same way, so you can use it control the power level and delivery on a 4t. Say you're in the woods, you come up to a sweeping turn that would require a down shifting a 2t. This is where the 250f has it all over the 125 2t, you just hold the gear and roll on it. As you come through the turn and pick a line settle in and clutch it a bit to got the rpm up into the meat and off ya go. It usually only takes a second for the bike to get into meat. The power will be less than the cr250 and can tuned to be VERY smooth with great bottom end torque. Just be VERY cautious buying a used 250f.