I haven't used any of the other programs, but REW really saved me a ton of frustrastion and money! I traded in my DIY sub for an SVS 20-39PCi. I set up the SVS and played some of the vaunted dvd's (Toy Story 2 opening, Finding Nemo whale and Darla, etc.) and was so depressed that I had just spent the cash on something that didn't produce any decent sounds at all. But, I thought that I would check and see if anyone else had this happen.
Thankfully, I found this forum and read up on REW and BFD's and promptly picked up a FBQ2496 on ebay and programmed it with REW. Now I can shake the walls with my house curve (one more thing I had never heard of!).
All of that to say that REW really is an amazing program. With the help files, I was able to download the program, study it, use it, and finalize the BFD filters within 36 hours. That is amazing! REW really is an incredible program! I can't imagine any other program being any more useful, especially with the midi interface to the BFD where REW will do all of the programming itself.
Tex