Have recently returned from a 6-night stay. I had problems getting the room originally booked and confirmed, but this was eventually sorted out. The breakfast buffet was better than during a previous stay many years ago. The gym was well-appointed, and managed by friendly staff. I wasn't able to get the headphone sound to work for the TV on the machine I was using, but did not bother to ask the staff. My main issue with the hotel was the variable heating conditions: boiling in some areas, freezing in others. As a result, some of the people in my party fell ill towards the end of the stay. All in all, I'd be happy to return here.

Very disappointing experience.
(1) I asked for a non-smoking room and got a small, cramped, mouldy box room overlooking a carpark. (2) Having just arrived from a long flight, I was tired and asked the receptionist if someone could bring my suitcase up to the room. An hour later the suitacse still hadn't arrived! When I went downstairs the suitcase was standing unattended just where I had left it in the lobby an hour earlier! (3) The staff were all as miserable as sin! Only positive: the breakfast buffet was varied and quite sumptious. Okay, I guess, if you don't mind a small, mediocre, reasonably priced hotel (100 quid a night), but otherwise better avoided.

This hotel is not as bad as some people say. We stayed just for one night before leaving from Heathrow for Thailand.

The room was clean, the bed comfortable, water hot and we had a good night's sleep. It was quiet and we could not hear the planes or the very busy A4.

We had an alarm call booked which was on time and a taxi booked which again was on time.

I would say this hotel is efficient, clean and comfortable. OK, not a 5-star, but definitely a 4-star. We didn't eat here because to be honest the menu was not to our taste and we went to look at the salad bar which was looking pretty sad, so we went to Macdonalds instead - cheap and fresh at least!!

If you want somewhere to stay just before or just after a flight, then this hotel is for you. I don't know if I would want to spend more time right by Heathrow Airport though!! The hotel is rather "unfriendly", but then their turnover must be enormous and they don't have time to make "friends". They are efficient and pleasant though and I didn't need more than this in the circumstances.

Spent the last 3 days there for one more business meeting. Arrived late evening for an early meeting start.

Rooms are just OK, not up to the 5 star rating (eg. no bath robe, fixed soap dispenser vs. individual amenities, Ikea style mattress boxes with sharp edges, hard mattress, etc ...).
The room was freezing cold and the fan did not work. Called maintenance, they fixed the fan, but apparently not the heating element as the temperature did not go over 16-17° for all our stay. (I could guess by the number of sweaters and scarves I had to keep on inside the room :-).
The toilet bowl was ... plainly disgusting, even so the next day after I asked for cleaning.
One of my colleagues a few rooms away did not have any hot water in his room.

We arrived at 7:30 in our meeting room and wondered if they mistook us for penguins ... this time the temp was probably not above 12°C. We asked for heaters and they brought a few, but it was not blowers, the room was really large and we ended up demanding another room as we started getting blue.
After a though negotiation, we ended up in another room with no windows - a real issue for a creative training session as it sets a low mood - but at least we were not freezing. Plus it really delayed our meeting start.

I suspect they had a real heating/AC/ Hot water issue at least in one of the aisles but they would not admit it.

Convention/business services was really poor, any simple request met with a suprised look and a promise to forward .. to whom?

Food is OK at both restaurants with a large buffet for breakfast and lunch. We had dinner twice at the more 'upscale' one but the Menu was the same both night with a very limited choice.

The only positives from this stay will be the gorgeous muffins of the afternoon breaks or free internet throughout the hotel (as in all Radissons).

Will I ever book it again ? NO, you get much better value for money at the Sheraton Heathrow.