What amp are you using? have you taken FR measurements in you room. how do you have your caps hooked up? There is not a single more capable ported sub commericially available than the JTR captivator that I know about. I suspect a setup problem is what you are dealing with if the Captivaotrs were beat by a couple of bp2000tls. I've heard Gorilla83's definitive tech towers with the powered subs and the caps put the defininitve tech subs to shame. Gorilla83 has nice Def Tech towers and he also owns a pair of caps. I'm sure he'll attest. It'll be a shame if you sell of the caps to 'downgrade' because of a setup problem. Gorilla83 discovered that if he runs the definitive tech subs and the caps at the same time he has a severe phase issue, and so we ran them a/b to check and both sounded louder seperately than when they were playing together. Another friend of mine counsil has the flagship definiitive tech speakers and he just turns off the subs because his seaton submersives are much better than the 18" subs in his Def Tech towers. Head over the JTR cap thread and lets get you straighted out and fixed up rather than selling off the caps.
As Archaea said, you definitely have a problem. I had the BP3000s (the 18" version up from yours) and there was simply no comparison between them and my caps. Output, extension, and SQ were overall beasted by the Caps. I recently sold the 3000's and replaced them with BP30s (same mains, no subs) and it sounds phenomenal.
Don't get me wrong, the 3000s sounded great for what they were - considering I picked up the set for 800 used. If the JTRs didn't outperform them I would be seriously upset!