If you are the DIY type or know a good cabinet maker, I strongly suggest that you check out the Hammer Dynamics Super12's kit($650). They feature a full-range driver, super tweeter, crossover parts, and are 97dB efficient. The Super12's deliver gloriously detailed, coherent, sound with deep, realistic, bass. The speaker enclosure is fairly simple to build if you have any woodworking skills and tools. Or, it should be pretty cheap to have made by a pro.
In fact, many people have stated that the Super12's were one of the surprising highlights of last month's 2001 Vacuum State of the Art Conference (VSAC-2001) in Silverdale, Washington.
Here's the link to Dick Olsher's review on EnjoytheMusic.com(the super-tweeter has been upgraded since the review):
http://www.enjoythemusic.com/magazine/equipment/0600/super12.htm
The Hammer Dynamics Website:
http://www.hammerdynamics.com/
A webpage devoted to Super12 teaks:
http://melhuish.org/audio/super12.htm
Do a search on both of these forums for "Super12" or "Hammer Dynamics" to read owner opinions:
1) audioasylum.com's "High Efficiency Speaker" forum:
http://www.audioasylum.com/forums/HUG/bbs.html
2) "The Single Driver Forum"
http://melhuish.org/audio/