Older vs. newer REL subs

A Goodwin's High End sales guy recently told me he thought the series RELs I own were excellent...but then, what does he know? I haven't compared them to new ones of course, but if they explode I just might.

My apologies to everyone, it is R8 that is the resistor that is the known failure point on older REL’s. 

Hilde45...its not for me to do your homework but ive bought 2 S510 for 2 grand  each delivered from 2 different Rel dealers within the past month, most will discount $250.00 before you even say hello.So with the free shipping they were actually less than 2 grand a pop...if your willing to spend 1500 on a T series sub why wouldn't you go the extra and get a S series (thats very close to their reference level as opposed to their entry line)?

The Ti or Tx series are mot aimed at home theater use.  They do well with that application but they are even better with music. They are the fastest, most responsive subs I’ve heard, by far. They start and stop on a dime.

The S3 SHO was a great sub and a slight upgrade from the T9i but really not worth it Hilde.  A pair of T9i’s or the T9x will already be overkill for you.  Room placement, room acoustics and setup will play a bigger role is good bass response than just randomly plopping down two S3’s or S5’s.

I sold my T9i to a friend and ghat single sub, in his room, has better bass response than any home system I’ve ever heard, RMAF included. Its all about the room, placement and setup once you get to a level like a T9i.  
Heres an analogy.  A trained driver in a 911 can do faster laps than a novice in F1 car.  
On a side note, I picked up my T9i basically brand new (open box) at magnolia for $750 and a S3 SHO (floor model, no box, no grill, no cables, for $1,000).  If I could score a couple of S3 SHO’s for under $3k for the pair I’d look at those as well.  
But anyway you go, T9i, T9X, S3 SHO... a pair will be more than enough and will probably impress the heck out of you.  You can’t go wrong with any of those...

@arafiq 
The KEFs are now gone, and the white sub doesn't go with the aesthetics of my room anymore. So the question now is whether I sell the white T9i and buy a pair of black T9is, or buy a single S/510 for now, and buy a second one next year.

If you end of selling the white T9i....please let me know.