I picked up a pair of noise-reducing headphones - cheap ones - today, and road-tested them both on the subway and in an internet cafe in the West End with moderately loud music playing, dishes clattering and one or two people talking. Although the amount of intrusive noise was far from being reduced to zero, it was definitely reduced, and I managed to listen to some fairly laidback plinky-plonky ambient stuff on the subway home without having to whack it up to killer volume like I might normally have to. Sound quality isn't the greatest, but they did the job, being to let me work somewhere that isn't my house, with extraneous noise reduced to a level where it's a lot easier to ignore, while listening to exactly the kind of inoffensive background music that fades into the back of my mind without actively interrupting the writing flow.
I passed by Offshore on my wanders; it looked busy - very busy. Lots of people with laptops, tapping away. I felt obscurely ashamed at the idea of going in and joining them, and continued on my way. At least in Bibliocafe, you feel like you've got some sense of privacy if you go to the upstairs comfy bit. I ended up in ICafe, a door or two along, which was ... okay, but far from the best environment for what I wanted to do. I think Bibliocafe is winning out.
I'm still running Scrivener through its paces. So far it's great.