Sell towers for bookshelves?

I'm currently running a pair of NHT 2.5i towers with a McCormack DNA 0.5 deluxe power amp and a Peachtree Decco as pre-amp/DAC (connected to cpu via usb). I may be moving into a smaller apartment within the next few months, and I was considering selling my towers for a pair of higher end bookshelf speakers (used most likely). I'm sure I could afford bookshelves with greater accuracy than my NHTs.
Does anybody have any input on this considering my amplification setup (which I would probably prefer not to have to change). Any suggestions for used bookshelf speakers? Thanks!
Almost forgot, I don't really have much of a price range because I haven't though about this too much yet, but I would probably look to spend up to $600 or $700.
The only reason I sold my Linn Katans was because I got the Linn Majik 140's. The Katans sound great and you can go aktiv in the future. Happy listening.
Not sure there is any advantage in selling towers to get bookshelves - they tend to take up the same floorspace plus you need stands. Unless you think you will have too much bottom end with the towers in a smaller space?

There are lots of choices to go with your McCormack (100wpc?). For 6-700 used (+ stands) you are unlikely to beat the NHT considerably - perhaps just something different. I also had Katans, sold them then bought some again. They would be in budget. Maybe Epos M16's. Most of the good stuff will cost a little more used (around $1k).
Thanks for the feedback so far. I'm just sort of feeling around as I'm curious as to how much I would have to spend for a significant upgrade in sound quality in the speaker department.
Meiwan, yes I do believe that the towers may have too much botom end (due to their 8" woofers) in a smaller place, which is part of the reason I was thinking about bookshelves. I will not replace the towers until I can afford something of significantly higher quality, however. So you are saying that for the increase I'm looking for I would be looking to spend around $1,000? or more? Thanks for this help.
And as far as other advantages over the towers I have read that of bookshelves and towers of the same price, bookshelves will generally be of higher quality. I am looking for more detail in my music now, and am willing to sacrifice low end (especially if I cannot play music as loud at my new place) so I figure bookshelves would be something to try.
I'd agree that to get a good increase you'd have to spend a bit more.

But my main advice is to get into the new space first. You never know what it'll sound like and what you need until you've got everything in there. The room is the most important component IMO. Well, the music is, but you can't really improve that.
Dollar for dollar a stand mount speaker should be "better" with the exception of frequency range, because a good portion of the manufacturing budget does not have to go into the cabinet. Grant it that you'll have to buy good stands, but that investment can last a lifetime if chosen correctly. Unfortunately, your budget might be too low to see much of a gain over your NHTs.

If I was looking for passive stand mount speakers today, I'd consider: PSB Image B5, Inage B6, Imagine B, Synchrony Two B & One B depending on budget; Paradigm Studio 60 is always a solid choice; Revel M22 and M12; SVS MBS-02; NHT's Classic Three.
Yes, sell the towers and get a pair of ProAc 1SC's to put on stands. As others had mentioned, the new room will need analysis before you will be happy. Be patient. Best to find a dealer that will loan you speakers to try with your gear in your new room. The latter approach is the only one that will give you a real sense of what is possible.
Bookshelves on proper stands can give your neighbors bass issues as well.
Maybe just sorbothane feet under the speakers? Or even a thick piece of carpet to decouple them from the floor.
Elevick, are you referring to my current speakers as far as decoupling goes? They actually have NHT's spike kit installed, allowing each speaker to touch the floor at the tips of four rather sharp spikes only. Still, I think that I would have less low end without the low 8" drivers and the large cabinet of a tower. Though again, that is only part of the reason I would purchase different speakers, the main reason being an increase in fidelity. I would also consider towers with just tweeters and midranges, though i figure I could get more for my money with bookshelves, as I am willing to sacrifice some dynamic range on the low end. I think the proacs are along the lines of what I may be looking for.
Quick question, how do the older B&W Matrix 804s compare to my NHTs? (With my current amplification)