Without actual sales data in hand I think this is a difficult claim to make.
I think it's just as likely that folks who pony up the money for an SSD are more likely to pony up the money for the 27" iMac. In other words, it wouldn't surprise me in the least to find that there are more 27" SSD-equipped iMacs ordered than 21" SSD-equipped iMacs. Heck, you can't even get the base 21" iMac with a factory-equipped SSD.
We are not talking about the imac BTO with SSD. And you are probably right there may be more SSD equipped 27 models. We are saying the 21.5 model, without BTO or stock outsell the 27 models. Actually the base 21.5 is the best selling imac out of the bunch.
We that being said, the 21.5's may well outsell the 27 even with the SSD option. No one knows.
You guys need to stop with the 21.5 getting inferior parts or drives. Makes no sense. Isn't going to happen and there is no reason for it. The only difference between the models is the screen size, extra thunderbolt port. Thats it. Internally they are the same, same motherboard, HD's, memory everything. The stock imacs use the same HD's. Same motherboards, same everything. Stop with the conspiracy theories already.
Like I said, the i7 in the 21.5 model is more expensive CPU than the i7 in the 27 model. Whatever SSD ships in the 21.5 model will be shipping in the 27 model. Same SSD, same features, same everything. For all we know both models will ship at the same time. Ever think of that? The shipping times are "approximate' not guaranteed.
As for the Air, they changed manufacturers for a same product, not put a inferior part "at the same time' for two different size imacs to people who waited weeks for their imacs to be built. No comparison to be made. Like comparing apples and oranges.