would depend....especially in older buildings, theres a lot that can go wrong with standpipes. You go up 5 stories in a 100 year old building with your high rise pack, connect to the standpipe, and that standpipe is rusted away and breaks when pressure hits it, then you're kinda screwed.

I would say if you are going to work off a standpipe for a quick knockdown, you'd better have a line being stretched in behind you just in case...