Keep SVS SB16 or change to REL S5 music only

After owning several SVS subs I think they're great for HT,  but not for 2-channel. I owned the SB13 Ultra and SB 16. I changed back to a JL Audio  F112 v2 and to my ears it has better, more articulate and defined bass. I recently switched to a REL Carbon limited sub, but I'm having problems with it being connected to my Jeff Rowland 625 S2 amplifier. 

How is the sound SVS campare to REL? 

I’ve had the same experience. I recently had an SVS PB 12 / 2 plus and it was an absolute monster.  Weighed 140 (?) pounds.  Could barely move the damn thing.  It sounded good, had all kinds of power and was pretty tight sounding.  

REL (T9i / Shmiko S9) has far more finesse.  I prefer REL and am actually becoming a REL fanboy.  They just disappear, widen the soundstage and clean up the mids and highs noticeably.  If I had an extra $1000 right now, I’d probably buy 4 Sumiko S.0 and set up a swarm...

I think that you may prefer REL over SVS.  I don’t want to take anything away from SVS because I think they build great subs, especially the higher end stuff like the SB 16 and SB 13 Ultras, but from what I’ve experienced, REL is so subtle and refined with finesse. I have only used the descriptive “finesse” with REL... didn’t really know what finesse was until I got a T9i.