Having visited both in 2022, we returned to the adjacent Swissôtel Stamford this year.
Access to the Gold lounge (I know from other threads that some here are expecting to reach that status soon

) would make the Fairmont more interesting, and I look forward to seeing reports in due course, but I would still choose the Swissôtel. It just felt much more comfortable, at the same time as being more modern in style.
Thanks for the "customised" advice!

Much appreciated! So the Swissotel is not an option in this case (story of why is a bit long - due to the fact I am going with someone who'll have their own room and theirs is booked through a channel which does not propose the Swissotel).