With BB2 they had the formula just about right, apart from the blatent opportunism at Helen's expense
Luckily their evil intentions were thwarted by Paul Clarke of all people
(The only rebel who really frustrated C4/Endemol and got away with it was Dean and his nomination strategy)
3 & 4 they lost the plot
5 they have completely lost the plot, shown a wanton lack of Duty of care of the contestants.
The show is completely ruined.