A little background: I'm picking up a DSLR for macro coral photography, general picture use, and vacation photos. I think I've decided on the 18-135mm STM kit over the 18-55+55-250 combo as for vacations photography, I don't want to have to constantly switch lens and there doesn't seem to be any great penalty (other than the obvious lower zoom range) for doing the single lens approach. I'm going to also pick up a 100mm 2.8 Macro (non-L) to photograph corals and other still macro shots (always from a tripod). I've got roughly a 1500$ budget so that leaves me with just enough wiggle room to pick up either a 40mm 2.8 or a 50mm 1.8.
Back to the question in the title. I know the 40mm has less stops, but has the better AF motor & has better video AF, something I may actually do, but is not a primary use driver for my decision. I know the 40mm has better IQ than the 50mm, but at the cost of a slower lens. However, the 50mm only has a 5 bladed aperture compared to the 7 bladed aperture of the pancake.
I know there are a lot of nice options if I was willing to go up in $$$, but if the overall budget was larger I'd probably be picking up the 100mm 2.8L macro before I spent more money on this prime.
I've done lots of research and searching (most of the thread topics that show up are around the time of the pancake's release and it was not widely used), and I'm having a bit of analysis paralysis on this whole thing. From the people who have owned both, which do you recommend given the above kit?