I got the 40mm STM after TD mentioned something about it in Out There and I saw the archive thread on POTN. It's freaking awesome on a FF body for general use. For $150 the 24mm EF-S will be hard to pass up. It will give the same field of view (38.4mm 35mm EQ) come to think of it. That might be the way to go.
Aw piss, I just saw it was an EF-S lens. I was really hoping it'd cover FF, not sure why I thought they could make such a small 24 given I have their other new 24 and it's three times longer. 
