How are you getting back to the central belt from Inverness. The choices are pretty much a FSR 170, or an NXEC HST. I like the HST feel - the Mk3 experience reminds me of what I imagine train travel through such beautiful scenery to be, and the lack of engine noise is a relief after the 156/158 you will have experienced. But it is once a day at 07XX. The 170 are very good and (apparently) much better than their siblings in England. FSR do have a specialist turbostar maintanecne centre at Haymarket, and many of the ones used on the Inverness route are ex-Hull Trains, and thus the seats etc are less tired that the FSR 170's which plough the central belt all day. Even then, they are mechanically fine and the large windows are great for such a scenic route - much like the 156's. The 158's were a bit too dark and small windowed for such a scenic route IMO.