Not sure about your price point but you should add Daedalus to your list. I heard the new Muse at CAF this weekend and it was exceptional. He has a number of other medium sized floor standers that are worth a look, including the Athena. All are very high efficiency designs.
Just for the record, a 'high efficiency design' is likely going to be about 100 db or more. The Daedalus speakers are 4 ohms with a 96 db sensitivity, when you do the math that means their efficiency is 93 db, which is not high efficiency, rather it is a moderate efficiency. Despite their impedance, they are lacking severe phase angles and are thus a relatively easy load for tubes.
Here's the math:
Sensitivity is 2.83 volts at one meter, efficiency is 1 watt at one meter (into 8 ohms the two are the same). However 2.83 volts into 4 ohms works out to 2 watts. Doubling the power from 1 watt is 3 db; IOW subtract the 3 db from the 96 db figure and you have 93 db efficiency.