i see this thread is a bit old but figure i will post with some of the recent ones (and also this page shows up as one of the first options when i google the sw-115 vs svs vs hsu etc).
I picked up a sw-115 from a local retailer here in canada and am very happy, i was upgrading from a cheapo bestbuy PA 10inch sub so its not exactly a fair comparison in the least but this thing does the reference series klipsch speakers justice imo. I agree with most of the folks here about the bang for the buck coming from svs and hsu etc but maybe less so for us northern folks when you start including border tax and all that jazz.
Once i turn my basement into a dedicated HT i do plan on picking up a second klipsch just to see what people talk about on here with smoother room response etc. Where it is now i dont feel any issues with its extension and love watching movies with this bad-boy. I now have to straiten pictures etc on a weekly basis because this think shakes the house, i actually put foam pads on one of my doors as well in order to stop the door from shaking when the 115 comes to life.
I know some people complain about the finish and it was mentioned here as well in comparison to the reference line from klipsch but i personally like the look of all black/matte finish and think it lives up to the klipsch name. I have yet to venture into the pre/pro separates world but would definetly like to in the near future and that is maybe my one negative, would like to have seen xlr inputs on the 115 but even then from all the research ive done on the matter it seems unless im running super long cables i likely wont see a difference between rca and xlr...
oh and just to hopefully steer some folks in the right direction as well, there are some awesome stickies on this forum on subwoofers that clear up tons of issues. i can guarantee if you own the 115 and it doesnt sound right for both movies AND music you have it set-up wrong via avr settings or you have a dud..
anyway hopefully people find this helpfull, and all that said i would love to see a VTF-15H in action or the svs options.