MG,
I think you obviously underestimate the performance of the "turbo-prop" which ScotAirways operate. The Do328 is the fastest a/c in its class and during climb can overtake the humble 146 with no problem. It is only at TOC that the jet a/c show their advantage over the Dornier. I doubt there is any impact on the schedule with which JEA used to operate with the 146 and the schedule which SAY operate with the Do328.
GOin' for GOld