I'd strike the Sofitel off the list. I did stay there a few times pre-C19 (while I still had Accor status and got lounge access and such) and it was pretty good. The games they were playing were minimal (like nickeling-and-diming people on DCC charges). But apparently, it has gone downhill since. Just from what I read. Check this review, for example.

When prices are low at LHR, you have a lot of good options, including the Courtyard, some of the Hilton properties, and the newish T4 hotels by IHG. When cash prices are high, the HP can be attractive on points, as can sometimes be the CP or the HEX (on points as well). The Hiltons can be good on award when prices are very elevated (due to their capping of points prices).

If you are open-minded and your point of reference is not really the HP LHR, you might want to check out the general threads on Heathrow hotels in the BA forum as well as the UK forum.