ATP's are very expensive to run compared with the JS41.
The advantage of having an ATP on the Scottish routes is that they could accomodate a fair amount of freight (i.e newspapers for the Islands etc) as well as passengers.
I know that a lot of the "advantages" (subsidies from various Scottish agencies i.e taxpayers money) tha BA and then BA Express / Loganair used to recieve for operating these routes, have been cut or withdrawn, hence the downsizing by Loganair.
Is this the end for Loganair? If you mean will they go back to just being an Islander ambulance operator with the occassional ad hoc charter - probably, it happened before in this almost identical scenario.
As for Eastern, becausethey base nearly all their fare structures on the 1st class return rail fare, they are very successful on the routes that would otherwise mean a night stop if you went by road or took the train.
Where there is greater demand than the JS41 can satisfy, they do the sensible thing and utilse jet (E135/E145) aircraft, which are also a great success.
I cant see Eastern ever operating the ATP, it's too inefficiant for their operation.