great bookshelf speakers vs 12-18 k floor speakers

I have a pair of B&W CM1's on stands supplemented with a pair of 2700W Carver Signaure Subwoofers.

I'll take all comers.

I'm adding my 2 cents to the Joseph Audio Pulsar recommendation above. They are a most attractive-sounding speaker and were very capable in the bass when I hear them at the Montreal show in 2010.

Of course at the price they had better sound good but the fact is that they do. IMVHO they are one good argument to support a "yes" to the OP's question.

For less money, and in a room which won't let you place a speaker far from the wall, the North Creek Kitty Kat is another high performer, with remarkable low bass in a tiny box.

i second the opinion on the totem mani 2's. awesome speaker. for a room that size and depending on how much bass and loudness you are looking for, will determine if you can go with a bookshelf speaker or not. i had a room a little bigger than yours (24ft long) and went with floor standing usher speakers. huge difference, more full sounding, easier to drive, overall a good move. BTW: i even teamed up the totems with a pair of subwoofer which was better but hard to get them dialed in. i also went from a pair of mani's in my other smaller room to the usher x-719 and i like them better too. much easier to drive than the mani's since the mani's have the isobaric woofer arrangement.
good luck.

You know-- recently I was listening to a small pair of active speakers (the Audioengine speakers at about 350 bucks a pair) in my girlfriend's studio apartment here in Manhattan.
The bookshelves behind them serve as diffusion and the lumber planks running across the loft ceiling in the apartment work as diffusion too I'm guessing and they are about 6 to 7 feet apart and about 7 feet from the listening position.
Using uncompressed files from an iphone and a macbook, the sound is stunning.
In my 20 years in this hobby, I have many many times heard sound from ridiculously expensive set-ups that couldnt hold a candle to this little 'system.'
Case and point-- I recently got back from the Axpona show in New York and lemme tell you- my girlfriends Audioengine speaker set-up puts some of the 100 thousand dollar rooms there to shame!!!
This is NOT because these little speakers are "better" than those MBLs and Thiels etc.-- but because they match her listening room space perfectly and have more than enough power and bass in there for the low to medium levels we listen at.
Hearing these stupid little active speakers in that room-- throwing a huge soundstage with incredible low-level dynamics (probably due to the built in amps)-- and producing more than enough (even too much) bass with symphonies in that room-- has made me sit up and take notice.
So to answer your questions-- the room is a huge factor and so are your listening habits and amp power etc.
I have many times heard great monitors like the Totem Manis and the Model ones absolutely demolish 30 thousand dollar systems on 'you are there' believability.
Should a smaller Proac or a Spendor or a Totem not have enough 'whomp' for you-- you can always add one of the myriad wonderful small subs on the market-- or preferably a pair (per many experts). Many of today's subwoofers are not the old boom and doom boxes of yore-- they are DSP controlled and very easily integrated wth todays monitors.
So say, a pair of even the diminutive Spendor 3/5R's with two Rel subs- one on each side and well set up-- could offer dazzling soundstaging as well as to cry for tonality.
For a punchier and bigger sound-- use a ballsy amp and a pair of Totem Mani 2's on heavy stands with the Rel or Fathoms or Totems own subs and that system would no doubt shake the very foundations of your building with Mahler's Resurrection symphony or something and frighten the neighbors with the soundstage spilling over outside into their dwelling.
Bottom line-- Yes. Monitors with or without subs are often better integrated sonically, less obtrusive and surprisingly 'full-range enough'-- especially with a modern sub or two.

My room is 15' x 21' x 8.25' basement room. I have had largish floorstanders Snell A IIIi and Snell CV. Full range single driver systems from Omega (Compact Hemp, Super 6 Alnico, Super 8 Alnico XRS, all augmented by a pair of Deep Hemp Subs)and Lowther Medallion II back loaded horns. My curent and final system is a pair of Shelby + Kroll Nano Monitors with 2 Woffer Monitors ($3600.00). The synergy between the Nano and Woffer is flawless. Deep clean bass with a perfect imaging, awesome tonal balance, and a full soundstage. 3D effect all over the place from a diminutive 2 channel system.
Search the site and read what Tim Kroll has to say about his design. Calling him direct would be best due to a recent lightning strike that took out his email.
Although Tim recommends Class A SS your Rouge Amps and other gear should work well with the S+K speakers.
Good-luck,
Rodge