Any high-efficiency bookshelf spkrs

I'm putting together a second system that will have a low-power tube amp/integrated and bookshelf speakers. Amp may be 15W or less. Any bookshelf speakers that would be a good match? Thanks!
Reference 3A DiCappo
Consonance Eric 1
Coincident Triumph UHS
Zu Tones.
I am in the same position and have read (not heard) that Omegas are very good as well. I am considering their Super3XRS.

What are you considering for amplification? I am looking at either a shanling MC-30 (inexpensive and flexible) or Cary 300B SEI (used, more expensive and less flexible).

Devore 3s
Thanks for the responses. I'll look into those. Not sure yet on amplification. I'll look into the Leben and Stingray II integrateds, and others. Mostly listen to 50s jazz and jazz vocals, some other stuff.
BTW - power and bass are not priorities. This is an office system -- don't want to disturb the neighbors.
Post removed 
Own the Coincident UHS TRS Signatures they are very detailed and musical. Listened a great deal to the DiCapos and they are also very good, image well. Either is very good.
FWIW the Stingray has a lot of power, much more than the 50 watt rating implies. I had one that drove Maggie 1.6s with ease to moderate levels!
Before spending more $, try to audition the Silverline Audio Minuet ($600/pr list). Like all of Alan's speakers, they are easy to drive with flea-powered amps. I was shocked by the performance of these tiny monitors at HE2007 in NYC.