Knee Trembler,
I am with NSF on this one . . . . . but , I can also tell you that if I had to give up a shiny 737 for some ratty ol F27 (hell even a shiny new ATR/Dash ) I would probably feel damn uncomfortable with the LACK of surplus performance/ability to avoid icing etc. So, as per the netjets philosophy it is the difference that makes the difference.
I have seen guys come off LHS TP onto LHS 737 and survive, equally I have seen a few more that all too evidently did not have a lot of spare capacity for the first 6months or so.
And that, is not IMHO a good thing.