Ah, but they used to have download restrictions. Thankfully D2D has come around.brain_stew said:At the very least some of ENB's features will work, possibly all of them if you don't update through GFWL.
You are free to download the game as much as you like. No restrictions.
You don't have to use the download manager, but if the download fails mid-stream, it's very unlikely you'll be able to resume via firefox. The manager is annoying, but its memory bloat is low compared to previous versions and it's not terribly intrusive. Just deal with it.