Not read the article
I think the majority of complaints will be about the customer service side and billing, we see quite a few posts on here about the 'offshore' service centers
For the vast majority of users there will never be an issue, but there are always some who experience a horrible time with installation/faults etc . . . no different to any other global company I guess.
I've never had any major issues, but if BT had fiber in my area I'd probably be long gone . . . in fact still thinking of going anyway, not because the service is bad, simply because of the pricing strategy and the thought of getting some muppet in Mumbai if I ring for a better deal