I'm guessing the 900 and 175 are going to get treated as the avro was, a mainline aircraft. Therefore normal sized roller bags will be allowed onboard and the policies for the -200 are just specific to that fleet.
Appearances are indeed deceptive... as are opinions. I value your opinion Mike, but I won't expect the seats on the 90s to be the worst in the system. Lumbar support and other comforts are a matter of opinion, but I'll keep the fact that you're vehemently against the new comforts of the 900 in mind.
AZJ