So, W3TC is the best and I using it on my websites. But I found some bug.
I use W3TC on WordPress 3.4.2 Multisite and single site. Page cache - disk enchanced, DB cache - APC (User cache), Object cache - APC (User cache). APC.shm_size set to 128M. Php-fpm go to (maybe) deadlock when I try to purge user cache (db, object) by hand or by wp-cron. And then php-fpm not responding, need to restart php-fpm daemon.
Server software: frontend - nginx 1.3.8, backend - php-fpm (php 5.3.13) + APC 3.1.9 (mmap memory, pthread mutex Locks locking).
I try to remove memcached (and memcache extension for php) but no luck.
P.S. Sorry for my bad english ;)