I would suggest that the only valid comparison would be between different garments, by different makers, on the same person. This is a good point. When I was trying to educate myself about suit terminology and fit, some of the most helpful threads I found were on London Lounge where someone would post pics of suits or jackets from different makers. Done this way, it was fairly easy to see differences between them. I think iammatt had a thread over there like this with something like 5 different jackets.