Hello nguyenmac, RehabMan.
Migrated to 10.11 (fresh install, pbi-ce 6.4.4). It seems system is working fine.
Found one bug. Battery disapeared from top panel. In "settings > power save" battery charged 0%. Show battery not selected. If I try to select, it automaticaly deselects after ~1s...
if your freezes not broadwell depend, you could try ec-reset. it helped me on pb 4530s.
Originally Posted by RehabMan
EC reset: shutdown, remove battery, remove AC plug, hold power down 30 sec, put everything back & restart.