18 month contract with BT would be just too long for me.
A lot can happen in 18 months, how much would BT charge to end your contract early,£10, £100 or more.?
I personally wait for a couple of months or so, & see what happening with FTTC, by then other isp's might have things up & running with fttc, like BE.
I'm desperate to move to FTTC, but I'm prepared to wait.