I'd imagine you have a lot more experience with Sky than me - however I will have to disagree.
When I first took out Sky Fibre Pro back in 2012 - You could indeed speak to some very knowledgeable people.
However, the twice I've had to call since those days, one of which was for a lightning strike that killed a line card in the cabinet - Sky were adamant that I had to pay £60 for a new router before they would even help. I managed to get it for just £5 delivery and I even begrudged paying that - I was without any internet connection for a few days waiting for a damn router to turn up.
In fact, in that instance, even when the BT engineer came - he was adamant it was not BT, it was Sky's equipment at fault. Imagine his surprise when he actually bothered to look at the fault in detail and, despite me relaying all the facts to BT and Sky, he had to go find the problem for himself.
Recently, I upgraded my father's connection to Sky Max - and they were also adamant that, despite him having a 52,000 sync rate, that there's no problem with his line only performing at 40,000. That issue seems to have resolved itself, but, I wouldn't trust most bargain basement ISP's, frankly. I've heard too many cases where folks ring up (And this isn't just Sky) and getting nowhere because they are stuck with scripts and nobody actually being able to "help".