I'm not sure it will affect you, so don't worry too much, as it is the same for all ISPs that you can get.
There are two ways you can get ADSL Max which is all you can get. The old way using BT Centrals rented by the ISP, and the new way using something calle IPSC (IPStream Connect).
IPSC is a sort of half-way house so ISPs can get your 20CN connection into them through their 21CN links.
I think it is only the full 21CN ADSL2+ products that get the occasional problem, though I can't be sure.
See my
WBC/WBMC/IPSC page for more detail.
Of the three I recommended I know Newnet use IPSC for the old ADSL Max. I expect the other two also do, but haven't seen any confirmation.
The main trouble seems to be the BT Noise Margin management goes crazy so people get very slow connections. No ISP seems to be able to sort it out quickly when it happens, but it only seems to happen to a few customers, and I think the ones I have seen have all been full 21CN ADSL2+.
In a way perhaps I shouldn't have mentioned it. Just wanted to prepare you if anything odd happened though.
What is certain is that with all of the three I gave you they don't throttle or traffic manage, and no significant congestion. So 99% certain to be far better than Sky Connect. Also they are all monthly contract.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - O2 Standard.