Of course they are. A few years back they had nearly disappeared from the market. I think the advent of the Internet (information) age and the subsequent proliferation of the DIY community has been the primary reason for the new found interest in high efficiency designs. Lets face it, single driver speakers and open baffle designs can be very inexpensive and very good. Low entry prices will always change a market.
Enjoy,
TIC
Enjoy,
TIC