While everyone is waiting for Mojo's review I thought I would post my thoughts now and see how my initial thoughts stack up against his.This was after only about 45 minutes of listening, so take it with a grain of salt.
The SVS PB13-Ultra has a linear response inspite of not being a digital amp and still retains that initial rush giving it that sought after impact for movies. The PB13-U has a smoother sound than the punchy PB12-NSD that I have and feels like it goes much deeper than the little PB12-NSD as the couch was really moving, even pantlegs were moving from the sound waves in mojo's 4000cf room during the depth charge scene in U-571. While watching the Eagles Farewell Tour DVD - Dirty Laundry, the thump the little PB12 had which became annoying, just wasn't annoying with the PB13. The thump was smoother and sounded lower, it was nice. We also listened to some Eric Clapton and the PB13 was there in the background as it should be.
The EP600 has such a nice textured sound that it allows this sub to achieve that transparency that some of us are looking for in a sub for music. The EP600 easily fills up a room with LFE and still rocks the house. Even though it lacks the initial punch of the analog amped subs, even the EP350 has more attack (IMO), the analog subs appear to lack the presence of the EP600. The entire room seems to become part of the experience. The EP600 has something in its tone that is warm and inviting, very pleasing for music. For movies this quality allows for a longer, lower decay of the sound and the sounds are more expansive, it invites you into the movie, as in the aforementioned Depth charge scene, the rumblings seem to go on longer and you feel them all around you with the EP600, something the SVS didn't do for me. During the Eagles DVD, the 600 had a very pleasing all around you effect as well that is hard to describe.
Does that make the wait easier or harder?