Can somebody explain the appeal to me? Not trying to start a flame war, just trying to understand.
A 24mm pancake (which won't have IS) seems a bit redundant with the 24mm 2.8 IS, which by all accounts is a very good lens, has USM and which Canon cut the price to a much more reasonable level. The size seems kind of irrelevant once you put it on a 5D, 6D or other full frame body and for an SL1, you end up with a 37mm lens which is barely in the wide-angle realm.
Do people like these pancakes just because they are cute (no argument there)? What am I missing?
The appeal for a 20-24mm pancake on crop is definitely there. Before I went full frame, my 20mm USM was basically permanently attached to my rebel. The biggest drawback to me at the time was that it wasn't wide enough. I would've preferred 16 or 18mm, with the 2.8, but I certainly couldn't have afforded the 16-35 2.8 L II at the time.
A ~24mm pancake will definitely not have (or need) IS. I would think it would be EF-S and also slower than 2.8 as well, for further differentiation from the new non-L IS prime. But who knows?
As for me, I'm actually thinking about grabbing the new 10-18 and just modding the rear mount to fit the full frame.