We went to Pacha restaurant last summer on a saturday in august. Since the club really starts going around 2 or 3 am we had a table around midnight. The food is good but stands flat versus El Ayuon and Km5 but it was really worth it. So my recommendation is to order a table at that hour. Otherwise you're "forced" to enter a calm club and buy expensive drinks.
I'm not really a Pacha fan anymore but if I'd ever go back I'll definitely eat at the restaurant.
One last thing, try to book a table in the inside part. Nicer atmosphere and the air is better, was too humid on the terrace, garden or whatever they call it.