Why why PFI?

Now correct me if I'm wrong but building something with the Private Finance Initiative (PFI) compared to just borrowing the money and building it ourselves means:

1) It costs obscene amounts more
2) Is likely to be a shoddier job
3) Is more prone to massive overruns
4) That we don't even own the thing we've built after we've finished paying it off in 30 years time
5) But it allows Gordon Brown to do some dubious Enron style 'off-balance sheet' creative accounting to pretend that we're not really borrowing the money, oh look aren't we prudent!

Now, it seems that we are doing the borrowing for the private companies ourselves.

So what is now the point?