Well, I like the VTF3, but one of my placement options is between my couch and wall with 16" of width. This subwoofer is 17" with a sidefiring configuration, and the woofer would be pretty much wedged snug up against the back of my sectional which I don't think would work too well. Although this may be a silly reason, I feel like all of the adjustability and tuning options on the HSU would be more of a hassle than I am looking for, but maybe that wouldn't be the case, not sure. So I have possibly ruled out the VTF3, but the VTF2 is still an option. I am surprised you prefer the 2 over the 3, as normally bigger is better.
One thing I really like about the SVS is the 5yr bumper to bumper warranty, and I really like the electronic protection circuitry on the SVS that prevents the unit from being driven too hard. Seems like this might help avoid damage if accidentally driven too hard. Although this may seem petty, I also think the metal grille looks really cool on the SVS, assuming equal performance with the other options. I also like the extremely linear response of the SVS, it is one of the flattest I have seen with very low distortion numbers.
I try not to be overly brand loyal. I think the HSU speakers were the absolute perfect option for me at that price point for a number of reasons, but I don't want to rule out any particular brand in regards to the sub I choose. I am extremely value conscious and want to make sure I get great value for my money and a product I will be very happy with for many years.
As far as rythmik, the price is good at 599 shipped, it seems well regarded, but im not totally sold on the servo technology. It certainly does not seem to hinder the sub in any way that I can tell, I just don't seem to have a clear understanding that it is the ultimate technology for a superior subwoofer.