retail price on vmps' top-line sub is $700. compare the specs of the vmps larger subwoofer on spl, frequency response, & distortion to that of *any* sub, including rel's top-line $3k model. re: the stratus, i would prefer *no* sub, to the stratus, regardless of price. the reason i had a chance to hear it in my house at all, is that my brother-in-law brought it over after failing to get it to integrate w/his proac 1.5's, in his ~13x17 room. they were on the way back to the store. too much loss of transparency & imaging...
i *have* heard the more expensive rel's & the top-line velodynes, but not in my house, only in stores. i have yet to hear a set-up w/seamless integration, or where the bass frequencies didn't draw attention to themselves. perhaps all the stores are incompetent, but for ~$2.5k-$3k *each*, for these subs, i'd expect a bit better.
ymmv, doug s.