Hey Din!
Hmm. Well, you got a lot of tweaking to do, now don't you? The "problem" with the SVS sub is you have a variable phase knob. Not just a 0/180 switch like most subs. The bottom line is to set the sub so it doesn't sound like it's competing with the bass coming from your other speakers, but is an extension of their bass. Mine personally is set to 180. Other factors would include the placement of the sub and the distance setting you have in your receiver.
Not having heard the VP100 I can't in all honesty say "YES, upgrade", but I use the VP150 and my room is 15x20. I sit 13 feet from the screen (and center channel). At 8 feet, you're probably good with the VP100.
As far as the EzSet built in SPL. It works...ok. But You'd be better off with testing with a test disk, like AVIA and using an SPL. I have both the EzSet (in the remote) and a Radio Shack analog SPL meter. I use the Radio Shack one, probably moreso because it's easier, but you can utilize a manual setting of the SPL in the remote. It can get tricky to set use the manual SPL in the remote, play the tracks on AVIA and makes setting changes on your receiver, but it can be done.
