My personal opinion is that the 250 4t is much closer to the 250 2t than it is to a 144. Also the 4's are much earlier in their development and my guess is they will be more than equal very soon if not already. I know several racers that are much faster on the 250F's than they ever were on anything else out there. Watching Josh Grant at the MCI or Villopoto at the MXDN shows just how close these things are to the 450's and we all know even Bubba couldn't compete on that 250 2t against the mighty 450's, you just had to ask him. ;)