Well, I did use one for a bit, but I ended up moving it to my bedroom system. I am thinking about getting one.
However, I'm just a sucker for big, full range speakers! I like to run my front L/R speakers full range, even with a sub in use. In a lot of action movies, there is prodigious deep bass in the front L/R channels that is independent of the LFE bass. And, yes, sometimes it is directional, i.e., I can hear the roar/rumble on one side more than the other. If you set the fronts to SMALL, then ALL the deep bass and LFE is sent to the sub. I also have tower speakers for my surrounds, and I also have them set to LARGE, so I get deep bass coming from behind me as well.
The other reason I like/want speakers that go deep is for two channel music. I like speakers that can more fully produce the bass that is in the recording without having to send it to a sub. When I do use a sub, I like for it to just augment the deepest bass a bit, and not try to reproduce the bass that is higher and should be coming out of the L/R speakers. Yeah, I know I'm in the minority in my thinking.