>> So basically if I am on a VP with other users from isps who have huge off peak download limits (say p2p downloaders) then I am going to get stuffed because of them.
Sadly yes :/
On the up side more and more ISPs are having to cut back and introduce caps etc.
Exchange contention was particularly bad in the evenings on a heck of a lot of exchanges last year.. (before ISPs started introducing FUPs etc).
It really only can take a couple of heavies to upset a VP (as I know first hand)
>> Have to say I hardly got any slowdown (thurs) afternoon and my connection since then has been excellent.
Possibly is a couple of business users utilising the network then, and they "broke up" early on thurs afternoon.
Its possible that in your town theres a couple of businesses (a lot of ISPs dont impose caps on business accounts like they do with the home accounts).. and a few of their employees are perhaps heaving utilising the connection to download stuff they cant at home.
(Just guessing).
>> Any other solutions......
Wait for BT to notice that your particular VP is running a bit hot and upgrade it.
Have you checked the exchange checker here.. not all checkers are up to date since BT only release the info once a month.. so even the most up to date can still sometimes be behind until BT issue the next batch of info.
http://usertools.plus.net/exchanges/