When I did my 1st Class ALR last year, I was amazed at the difference in First Class complimentary offerings on different TOC's.
VTEC were by far the best. Attentive service, alcohol included after 11am weekdays, and even the weekend service was plentiful, from my experience. VTWC was good too, although I only did one run with them, from Holyhead to London on a breakfast service. Couldn't complain.
GWR was, well, OK, as was XC but nowhere near as good as the above. Seats on GWR were great though. The worst by far was AGA. Shocking! It didn't even look like First Class and the offerings were minimal - a can of Coke for example was a drink they didn't include.
As for the TOC's on routes in the South East. Pointless! Southern for example, the seats on one train I travelled were no different in First than the ones in Standard, save for whatever you call those headrest cloth things. I didn't travel on TPE at all, and the only Scotrail services I used were Standard Class only, and my one journey on EMT in First Class, purposely to have their breakfast, didn't go to plan as their kitchen had a fault.
A real treat was the ATW "Gerald" train. 3 course meal with a glass of orange (alcohol extra). The food was nice, and well presented, and the staff were great. The sleeper services weren't bad either, with Serco having the edge.
I would welcome the level of service I experienced on VTEC on ALL 'InterCity' TOC's, and it being scrapped completely on South East TOC's.