I recently purchased the SVS 20-39 CS Subwoofer. After much deliberation and research, it finally came down to just believing the thousands of testimonials and hoping for the best. I have not been disappointed. Initial Impressions: I personally had a pretty decent DIY model before I got the SVS and while the SVS goes deeper with less distortion, it certainly doesn't "rip up the floorboards". I was expecting it to be a whole new dimension in sub bass peformance and what it really is, is a very clean, deep and seemingly bullet proof sub. It has never even sounded close to bottoming in my system. It does indeed rattle the walls a bit, especially with sources such as Titan AE (I recommend renting this video to get a "feel" for what the SVS can really excel at). I also noticed that it took a few days before they were broken in and sounded their best. Music: It's a fairly musical sub. A good test to see how musical a subwoofer is, is to play some good music that has an actual bass guitar in it and unplug your mains. A bad sub will go "thunk - thunk-thunk" and a good sub will go "boing-boing-boing" In other words, a musial subwoofer will have a more "round sound" and will not be "one note" or plodding. You should almost be able to hear the "fingers on the strings" as the bass progresses up and down the scales. It will sound more like an instrument and less like a speaker. Stanley Clarke is a great CD for this test, he really puts that instrument through it paces. The SVS is indeed able to keep up with the transients in Bass music very well. I did detect a bit of the "pluckier stuff" getting lost a bit in the massive tube and sounding just a tad muffled, but I attribute this to the downfiring woofer and the considerable distance from the driver to the port. I realize from a physics standpoint that this really shouldn't matter, ... Still, to my ears, some parts of the Bass scale sounded a bit "lost" in there, while others had an ever so slight "congested quality". Overall it was far superior to the lower end Velodyne I had tested in the same way and this minor shortcoming was all but unnoticable with the main speakers back on. My DIY's did a bit better musically, but again, they were using 10 inch Woofers and were optimized at 30 hz and could not go anywhere near as low as the SVS could. It's all a trade off , in my experience, deeper extension has always seemed to equal a bit less upper mid bass detail. I think the 20hz model is a nice compromise here. Home Theater: The place where the SVS really shines is in DVD home video. My God, these things are amazing. They really throw out a huge soundfield. For the first time I can hear deep bass emanating from my rears when the space ships fly overhead. The bass rumble starts behind me and proceeds to move in a huge wave across the listener to the front of the room. The SVS really blend well and fill the whole room. I did find that placement of them really needs to be in the front of the room (at least at my house) because they are fairly easy to locate if you place them too close to your listening position. Bass is not as "non directional" to me as it seems to be to others... Especially when discrete LFE material is being sent to the Sub. The "BOOM" in movies is going to sound like it's coming from the sub if the sub is sitting next to you. I find it very distracting if the boom is on the TV screen and the actual nosie is coming from my left side for instance. Plus I feel the "Bass Wave" needs some distance to unwind if it's going to be able to blend well with the other speakers. Overall Performance: Overall the SVS is an impressive performer even without the use of an equalizer. They are flat enough to suit me in my environment without needing one. That says alot about their performance and design. So while I agree with some that it's not a religious experience, I think bang for the buck they do a very good job and are major improvement over any Sub I have made or used in house. Having never compared them to something that I would consider "in their league" it's difficult to say if the minor shortcomings are necessary in order to allow them to excel in what they do best. The only way to know for sure is to bring home something that IS in their league and do a head to head comparison. FWIW, I have ordered one of the HSU VTF-3 subwoofers just to see how it can stack up. Should be a good shootout. I know my Wife is pulling for the HSU because she just can't get behind the "tube look". Me? I'm pulling for the SVS because I love Tom and Ron too much to send it back. Those guys have been amazing. I gotta say, Dr. Hsu is also a class act too. He will NOT make any statement of any kind in regards to comparing any of his products to SVS, so don't even bother asking. He will simply ignore the question as if you never asked it and stick to talking about what HIS subs can do. The best you will get out of him is for him to compare the VTF-3 to the other subs in his line, and he will leave the rest of the research to you. I thought that was pretty cool. Still, I really wanted him to give me some idea of how they would stack up against each other... but I guess I will have to pay about a hundred bucks to find out. Still pretty cheap when you consider the overall cost. Bottom Line: I will say that the SVS has made a believer out of me. While not as musical as I'd hoped they'd be, bang for the buck nothing I have purchased has made more of an improvement in my Home Theater listening experience.