Thanks all for your assistance,
I had a call from Plusnet earlier saying the noise margin target was set to 6db so we'll see how that goes. Seemed to suggest it was already set so that is a little curious unless the exchange kit has been meddling itself... FTTC is an option but to be honest 3+Mbps that we get when it behaves seems fast enough for our use so not worth paying the extra.
Having cobbled together somethiing of my own I've subsequently spotted 2704n Linux Bash Script to Monitor ADSL on the forum which is better than my quick effort so we'll keep an eye on it properly now.
Cheers,
Alistair
