It's not my main thing, but I've done a little street photography with a 35mm camera. Even with one of these, with a much faster lens than the Rolleiflex TLR, you tend to need ISO 400 if only because not too much is going to just sit or stand there and pose for you (and it wouldn't really be street photography if it did), plus there is often shade from buildings on the street, even on a bright sunny day. I almost always use ISO 100 film for other things, but it's just too slow for most street photography. The issue is not really whether or not the camera has mirror slap or whatever or is easy to shoot handheld, but rather the film speed you need for a certain amount of action. If that weren't the case, Plus-X and FP4 would be the classic street photography films rather than Tri-X and HP5. Of course, other people's opinions, including mine, are no substitute for just trying it out for yourself. Who knows, maybe you can make ISO 100 film work for what you want to do.