I think BT have become more consevative with their speed estimates. I have Infinity and get a consistent 36Mbs download and 8Mbs upload. I have recently been getting a lot of dropped connections and suspected by HH2. BT were/are offering a speed upgrade and a free HH4 if I re-contracted for 12 months. When I first checked the speed estimate would be 68Mbs download can't remember what the upload speed was. this seemed well worth getting.
I got sidetracked over an issue with BT Sport however when I checked estimated speed today it is actually less than I am getting, whilst I don't expect my speed to drop if I recontract the advantages seem to go away. I don't care about the PtoP throtteling as I don't use it.
I have also been given a TP-Link Archer C7 AC1750 Wireless Dual Band Gigabit Cable Router which seems to have cured the drop out problem when I replaced my HH2 with it.
SO I am happy with Infinity but will stay on my rolling contract.