Endless debate: monitor + sub vs floorstanding


Have made a simple system with Peachtree Inova and Proac Sig 8 Tablettes on sand filled stands. Lovely sound I am quite pleased with though I'm considering either supplementing my beloved Tablettes with a sub bass (most likely the new Rel T5) OR grabbing a pair of full range floorstanders (likely used Proac as well).

Any thoughts on the relative merits of the two setups in terms of expression, detail, dynamic spectrum, musicality and also flexibility? Intuitively, it seems I may have more opportunities to play with and fine-tune the experience using Tabletttes plus sub.

I realize there is probably no perfect answer here. Unfortunately, my opportunities for a good side by side listening comparison of the two systems is pretty much nil.
marburg
YOU LISTEN to justin bieber? I now no it is time to stop reading these postings. I can deal with reading the miss informed posters, but I draw the line at justin bieber!
Subs , well OK . Mine is 6' off the floor , built into the front wall , dead center , 18", crossed over at 40Hz , power by a bridged Luxman amp . With my speakers it's only needed for movies and pyrotechnics .
Best of both worlds, use both. I use both, Legacy Helix full range quad amped floorstanders with Legacy Extreme HD Subwoofers. This way I get a set of speakers that will go down to below 20 hz and then place the subwoofers to reinforce and enhance the bass. One has to hear it to believe it!
Room sound is the elephant in this room. One "leetle" 10" woofer in my old REL (150 watt mosfet) is plenty of bass for my hifi room...I have to keep the REL level under control or my walls would crack, but it is dialed in enough so level changes are minor (it's at maybe a third of its output seemingly, based on the volume knob). One of the things I think is a benefit of discreet powered subs is the ability to control deep bass output as otherwise there are no tone controls on my (or likely your) preamp.
My Rel T5 is only an 8" downfiring, yet it delivers vast bedspreads of sound. I have it set up in the corner, roughly 4 inches in and about 2 feet behind the left Tablette. The sound of Takemitsu's "From Me Flows What You Call Time" hits my chest cavity and auditory apparatus like the Shoemaker-Levi comet slamming into Jupiter.