There seems to be no master thread on the Radisson Blu es - do FTers have any personal experiences to share, of their stay there? Tripadvisor reviews are unusually harsh but the hotel website seems trendy - almost akin to the Indigo hotel chain in the United States.

I have no experience as room guest but I've arranged some business events there.
Yes, somehow trendy, nice hotel. Positive feedback from our attendees and hotel guests - no exception - and fair pricing.
It's opposite the current platform of the Leonardo Express to FCO and so obviously opposite the Termin railway/underground station. Maybe it's even closer to Vittorio Emanuele underground station. Good location, in terms of public transport and access to other areas in Rome, or elsewhere via Termini/FCO. For this reason, I think it's a good option also when the FCO hotels are not available or very expensive.
If you have a car or rent a car, the hotel building hosts a car park that is used also by rental companies with an office in Stazione Termini.

I just made a reservation here for next month and shall report in with a detailed trip report then!