OK guys so to give you all a quick update on my situation....
I finally ran out of patience with Virgin and decided to change providers, and based on the feedback from you guys I've decided to give BT a go. I've been able to organise free installation of a new phone line which may not sound like a big deal, but it's important for me because I don't currently have one which means I'm tied to Virgin for my broadband. Having a phone line opens up more possibilities in terms of switching to other providers in the future.
So my thinking is to give BT a go for a year and see how we go. I've gone for the Infinity 2 service so I might need to ask for some advice in setting up my new router to work with the R1 when it arrives, and all being well I should be up and running on BT by Friday 22nd September.
Thanks again to everyone that chipped in with advice, hopefully this should get me sorted