I agree. I've traveled by some new smart CSTC buses under JNNURM Scheme and I've made the following observations:-
.
Volvo AC Buses have broad seats made of thick velvet foam material with large standing area (CSTC doesn't run Non-AC Volvo Buses as of now). Routes like AC-1, AC-5 and AC-6 run Volvos.
.
AshLey...
more... AC (and Non-AC too) Buses have narrow seats with rag-zine foam material and narrow standing area. Routes like AC-12D and AC-20 run AshLeys.
.
TataMarcopolo Non-AC Buses also have narrow seats with velvet foam material and narrow standing area. Routes like S-45 and S-47 run TataMarcopolos occasionally (Other times with AshLey Non-AC).
.
PS: I haven't tried TataMarcopolo AC Bus travel since they are running on WBSTC Routes. I hope that WBSTC starts some AC and Non-AC Buses from Shalimar Station also some day :)