We recently stayed on the Executive floor at the regular Marriott LHR, not the Renaissance.

The guest room was very nice and spacious, in-room complimentary wired and wireless internet, with a provided Ethernet cable. The window was double paned, very quiet.

The Executive Lounge is on the ground floor and has nice offerings all day long. The breakfast offered cereals, scrambled eggs, bacon, sausage, ham, fresh salmon with capers and onions, multiple bread and roll options, fruit juices, and fresh fruit.

After breakfast, they put out about 5 large glass jars filled with nori (?) balls, edamame, peanuts, pretzel mix, etc. Also a large jar with cookies.

In the evening, they offer the healthy celery and carrot sticks, etc. Sandwiches on regular sliced bread. For hot options, they had lamb and mashed potatoes, another night was salmon and rice, another night chicken with rice or potatoes (I don't recall which). I believe they had another option, but I've forgotten. Soft drinks, juices, coffees, teas, and waters all day long. Wine and beer is offered, but maybe only in the evening, not sure about the times.

Later, several yummy dessert options, along with the cookies.

It is one of the most thorough food offerings I have enjoyed in a Club Room. Sometimes, the options are all fried and fatty where you really don't want any of it, but this was all very tasty and abundant.

A large TV and newspapers are available. Someone arrived just as the breakfast time was ending and I overheard the server tell the guest they could order breakfast in the restaurant for free. I wasn't paying close attention, so I would make further inquiry.