Hi Sarge,
I am happy with the Rel and it is better than my previous subs, Deftech procinema 1000 and SVS PC 2000.
There is more enjoyble midbass in the Rel. Though the PC 2000 use to dig sightly more deeper, I don't miss that. Gunshots and door slams have more impact with the Rel. The newer model 1510 is slightly more powerful and supposedly has more midbass as per reviews.
Other subs to consider are Arendal(10 year warranty and better build with HDF) , PSA, Rythmic, HSU, too. Pls take a look at these subs too if they work out cheaper.
The HT 1508 is good enough for music for my tastes and movies. Though I presume The T and S series would be better for music.
I needed a sub which would balance both.