Never been to one...But if the WCCC is against them, I'm for 'em...
I have been to one -- and sorry to say, I feel the "two miles wide and one inch deep" comment is accurate. The theology often was shallow. I also felt that the megachurch's marketing strategy was to loot smaller churches of the same denomination rather than to enlarge the circle of believers.
I also indicated that my experience may not be typical -- so I am open to other views on the topic.