You are normally allowed one vice at a time. Home Theater, regrettably, counts as a vice during the aquisition and update phases but ceases to be a vice if the whole family enjoys it.

Before you bother asking, no you can not switch rapidly from one vice to another and still have it only count as one...

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8