I use it with REW. It helped tame a couple peaks and I'm satisfied with the value/fun factor. I can't offer any real advice, because - for me - it was a "set it up and forget it" type of endeavor. The Home Theater Shack guys do a great job with that setup.
I think you still need a compatible sound card. I also bought the M-Audio USB MIDI dongle to download the settings to the BFD so that I wouldn't have to key them.
Some people have concerns about the BFD because it's not a completely "clean" device (i.e. it is not distortion-free). I don't worry about it, because I subscribe to the theory that distortion below a certain frequency has to be pretty epic to be audible.
Fun toy. I think it helps. I like it. I'd rather have an SMS-1, but this was a much cheaper solution. It can do 2 subs independently, although I have not tried this. Likewise, since you're using the line-outs from the BFD, you don't end up losing any voltage if you decide to use multiple subs (compared to using a Y adapter out of your receiver).
