That's a start, but it's more suited for smaller tasks I think, with the main benefit being that you don't have to clutter your code with type conversion. A string with custom (no) encoding does fairly well for holding the binary data as is.

It was actually memory/GC issues that got me to give up on the js implementation - it's very hard to prevent js from creating huge numbers of temporary variables, which then cause the system to freeze for several seconds while they are cleaned up.