Floor Standing Speakers to Monitors and Subwoofer

Who has successfully transitioned from floor standing speakers to monitors and a subwoofer system and hasn't looked back? I'm movng my system to a smaller listening area 12' x 14'. I currrently have Polk LSI15's. Looking to upgrade sound and stay around $2,000. Looking for tighter, well-defined bass; equally clear mid-range, airy top-end. Thanks.
Ive written before about my excperience. I sold my B&W 803S after several years and bought a pair of Nola Boxers with an REL sub "just to temporarily" have something for a while. I was astounded by the soundstaging airiness and pure ease of listening. Not temporary now.

The speakers are $1500 and subs range in price. The Nolas have been favorably reviewed everywhere. Hope this helps.
Yes. It depends on the sub, sats, and implementation. I heard a Classe/B&W implementation of the B&W PM1's and PV1D sub with Classe electronics. Classe is now part of the B&W group.

Anyway, the system was digitally oriented and the Classe electronics included a high pass filter in the digital domain to the PM1's, which increased their dynamic range without the hit in transparency and phase response you might get with an analog crossover. It was at a mfr's open house and B&W/Classe guys had done the setup, which was about as perfect as could be.

This was a KILLER setup for anything with no discernible flaws. No hole in the frequency response, no whoompy overlap, nothing out of phase. It really made the advantages of a mini-monitor shine--airiness, transparency, speed, lack of boxy resonances, wide dispersion without front baffle diffraction distortion, etc.--with none of the weaknesses.

Good sat/sub systems have several advantages. Good small-baffle sats throw a big holographic soundstage free of boxy colorations, and the sub(s) can be placed wherever bass response is best in the room, and tuned in with phase, volume, and crossover controls. You get much of what is attractive with panel speakers without a rig that doesn't visually and spatially take over the room.

There are so many KILLER mini-monitors out there that would make great anchors for a 2.1 or 2.2 system--Quad 12L2, B&W PM1, Totem Model One, Tyler D3M or D4M, PSB Synchrony One or Two B, KEF XQ10 or XQ20, any number of offerings from Dynaudio, etc. And although I'm a big fan of JL subs, that B&W PV1D was fantastic and matches well with the speed and higher reach required by mini-monitors.
Ooops, and of course the Boxers! They'd be a great anchor for a 2.1 or 2.2 system because they have higher sensitivity (90 dB) than most mini's with their higher handling capacity and of course are well-known for an endearing sound that draws you into the music. The high sensitivity and power handling mean setup should be easier and less dependent on a high pass filter to get good integration and dynamics.
You can't 'upgrade' from the Lsi-15s for 2000 dollars. You can get a different pair of speakers for 2000 dollars. I own them and play them is a similar sized room. Some times we just have to accept that we did it right the first time. Get 2000 dollars worth of CDs instead.
How about getting the LSi/9's and a sub or two? The LSi/9 has the same mid/tweet arrangement as the LSi/15 and they're only $599/pair through Amazon.. Then you can get one or two subs to blend and adjust the bass output to the smaller room. Rok2id has a good point. I haven't heard the Polk LSi line myself, but the LSi/9 appears to be a bargain for a pair of MTM monitors with ring radiator tweeters for $599.
Johnny how does the PM1 fare without a sub?