I used to wear liners + thick wool socks for trail work and it was great - never got a blister. Since switching to lightweight runners for backpacking I've kept the liners but lost the thick wool socks - now I wear two pairs of liners. Wigwam Gobi's as the inner liner and Wigwam Coolmax as the sock. Or Gobi's as the liner and cheap thrift store acrylic socks as the outer. The coolmax's are *way* too thick to be a liner sock.
I don't see any reason for me to go to single socks when I can just do two lightweight layers instead. They dry fast and I can switch out the liners frequently on a long trip - it doesn't cost much weight to take an extra pair of Gobi's. But then again, liner socks have always worked for me, and everyone's feet are different, so YMMV.