The worst is to get behind a Fokker 70/100 or a Dornier 328Jet - very slow and seem to create an enormous traffic jam in the Northeast USA.... .. .Those Dornier 328Jets (Dojos) are like mosquitos in the Northeast - they're everywhere........... .. .I think assigning slower aircraft to lower altitudes is smart. Overall, there should be an understanding among pilots flying the slower aircraft that they need to get out of the way - it's like driving in the States - slow traffic should stick to the right lane and let the faster traffic pass on the left. It's COMMON SENSE..... .. .Cheers