Hi ceetee, Here are my honest thoughts. I purchased the ULS-15 and had an opportunity to also purchase a JL Audio Fathom F113 version 1. The ULS-15 sounded very good but it did not have the output or the sound quality of the fathom. Obviously there's a huge cost in price difference so I know the comparisons are a little unfair. It got pretty loud for a sealed 15 but I ended up also purchasing the VTF15 mk2 3 weeks later, the ported version of this speaker. I have to say that I preferred the VTF15 over the ULS15. The output was better and I also liked the sound quality a little more. The VTF15 had about the same output as the fathom and maybe a tiny difference in sound quality. Put it this way if you didn't compare both of them side to side I highly doubt you would notice a difference. Having that extra output over the ULS15 to me was pretty important though. I am a bass head so I need output. I think both are great subs but I feel the VTF15 is the way i would go if space wasn't an issue and you were looking for that extra sound pressure levels.really eager to hear your comments on the ULS-15 since i might be purchasing a pair.... thanks!