Small system upgrade question

Hi all

After much deliberation, I grabbed a Peachtree iNova from Underwood Hi Fi for my Proac signature Tablettes. I'm running lossless and some 24/96 files from my iMac for the most part.

Walter L. at Underwood said I could supplement this in all sorts of ways, perhaps including one of the new, compact Rel T5 sub basses.

My question: would this be a worthwhile and significant upgrade? My little Tablette's have superb bass extension. I think they're rated down to 38 hz and I've never felt them lacking in the bass dept, though I understand a really good small sub like the T5 can actually improve the mid range of speakers its paired with. For about 500 bucks, is this a sensible upgrade? Better to leave well enough alone? Better ideas?
Integrating a sub is a challenge. Unless you cross over at the sub, you will not realize the benefits to the mid-range, which means more cables etc.
And a $500 sub is not going to be fast enough to work well with the Proacs.

Leave well enough alone.
Best to dump the Tablette's, and move up to another proac that has base. I have the Tablettes and tried dual subs and that was not very effective.
Tablettes 38Hz? Never! Unreal!
Otherwise adding a compact sub is the best idea mentioned.
BALDERDASH! Integrating a good sub is actually very easy and a lot of fun for anybody with reasonably attentive ears. A well designed sub like the REL can be magic. The "high level" amp driven input allows the speakers to do their thing, and you can set the frequency, phase, and overall level of the sub to suit your tastes. I scored a perfect older mosfet REL Q150E very cheaply (Ebay...$150!) and built my own neutric-speakon terminated cable for it. Due to some perhaps "psychoacoustic" phenomena it really does seem to "open up" the mids...highly recommended.
The way a sub can improve the rest of the audio band is to take the bass load off of the main speakers. So unless you have a way to employ 2-channel bass management the main speakers won't realize the benefits of a sub. This doesn't mean that you won't enjoy the additional bass provided by a sub.
BALDERDASH part deux: A well designed sub like a REL can indeed improve the overall sound of a system with speakers running full range...I would have doubted it but since I put my REL in the system it absolutely does what I said previously, and works this magic (or "audio band improvement") in other's systems I've heard also. Maybe it's due to the fact that the main speakers aren't choked off by a crossover of some sort...who knows...but work it does. REL should pay me for this endorsement...