Basically what airfrogusmc said. I was mainly shooting w/ a 24-70L. It's convenient, but the zoom can also screw you. If you're using a prime, you know where you need to be placed which can be helpful.
For slow moving subjects, you'll need at least 1/60th, and that's a pretty slow movement. So, high ISO will be important if you're not in daylight. I think I'm done with The Brick. I have a Zeiss T* 2/100 and 2/35. Both I've just got, but I'm loving them. They're making me go out and shoot, and that's good for the turd weather that's coming up. It's kind of tricky with street for manual, but I'm not missing many shots. I'm also trying to steer away from just pictures of people, and capture more of the mood. So, I am not totally reliant on AF. It's nice to have though. I have a few adapted MF's in the 50 range that are good, but none are chipped for focus confirmation, so the MF is a bit of a whore. Looking to alleviate that with a focus screen from (wait for it...) focusingscreen.com. Would rather have a brightscreen one, but that's not going to happen. 
I need AF for an event this summer, so I'm thinking before then (maybe soon) I will ditch the brick and get the 50L F1.2. It'll be my only AF lens, and is right in the middle. I just dug through my photos from last years event and 80% were between 40mm and 60mm. So, that's an easy choice.
Finally, I hate shoulder/neck straps. I got an $8 hand strap that goes from the shoulder strap "hook thing" near the display on the top of the camera, and screws into the tripod hole on the bottom. Never looked back. Best camera accessory I've ever bought besides the CF card. It also makes you look more like an enthusiast and less like a perv... I mean photographer. 
Haha. There will always be people that give you a wonky look. I have a few tricks to make them feel like they're in my way instead of me encroaching on their space.
