Cool, I've become one of those sub guys you mention. But I understand the bad rap that some folks here have concerning sub set-ups; some that I've heard have indeed sounded bad--mushy and thumpy, which would make mixing a nightmare.
What I learned, though, is this: integrating a sub effectively takes some time, skill, and the right equipment:
* you need monitors/sub that will allow you to direct the upper freqs to the satellites and the lower freqs to the sub.
(The BX5s I use allow me to cut-off the bass the produce at either 80 or 100Hz.) Otherwise, you'll be hearing a lot of overlapping low freqs that can muddy up the sound.
* you need to dial in just enough low end from the sub until the sound is smooth from top to bottom. It's important to resist the tempation to overdo it--the bass should not dominate, but rather fill in those low-end freqs that are missing with smaller speaker set-ups.
* while setting up my own monitoring system, I needed a week of evenings to experiment with freq cut-offs, sub volume, and speaker placement. And some reference CDs and sample mixes to compare on other systems. After some good effort, I eventually found a "sweet spot", where the sound seemed to come together seamlessly. But it took some good time and effort.
Personally, I'll never go back to a non-sub system, but I understand how personal this decision is for people. I also realize that my home studio (Yamaha 16G based) is not up to the standards or needs of many folks at this forum. I do work in pro studios, but only as a session guitarist; at home, I just need a clean, reliable sound for use with colleagues and friends. In this context, the sub set-up has made my mixes much more consistent, and the sound is so much more enjoyable to work with--balanced, punchy, with those extended low freqs that are clear enough to make mixing the bass no longer a guessing game.
Just my experience,
J.