In reply to a post by mlmclaren:

I've noticed that cabinets fitted using the BDUK scheme are all Huawei's, even in areas where BT's initial rollout was ECI.

It's a bit of an educated guess, but this might be down to the better vectoring support in the Huawei cabinets. My understanding is that the Huawei cabinets can, with the right hardware installed, deploy vectoring across all lines on the DSLAM, whereas the ECI cabinets can only vector lines on the same line card. It seems that Openreach are not going to make a widespread deployment of vectoring, but might deploy it in areas where it helps them reach their BDUK coverage targets.

It is also possible that they got a better deal buying Huawei cabinets.