Well, after weighing all the options I got the HSU STF-1 the other day! It is a good size for the bedroom, and I have it tucked in a corner. Disappears from sight.

From initial impressions, I have to say that the STF-1 does a very nice job of filling out the sound of the M3Tis. I am pleased by the richer, and deeper sound. I tested switching the sub on and off many times as I relistened to my music library. The sound is so much better with the sub on! Been playing around with the STF-1's bass volume as well, and it seems to be adequate with the dial set at the 10 - 11 o'clock position. For me this is just enough bass to be noticeable and fill out the sound, but also not too overwhelming.

In a couple months or so I might upgrade the receiver, but that will come after buying an Axiom center first! When it comes time to buy a new receiver I would sure like your opinions on a good one for about $500 Cdn. Anyways, I seem to be down the path to higher quality sound, and quite happy so far with my purchase. I'd like to give a big thanks to everyone who recommended the sub, and also for the replies to help me out with the decision process!