Thanks for your reply craigthemif

Yeah, I know the "exchange rate" isn't great, but I'm all about converting everything into Avios and building that up instead.

The thing that wories me is exchanging details over the phone, i.e. will they get the details right (especially if they misheard you)?

With exchanges done online, the details are entered in black and white, so less chance off somebody messing up. So I was just after personal experiences from people that's all