If you pay, the IC Pyramids is great value (rates start at 50 USD per night). However, the hotel is, like just about every resort hotel in Giza, very old and very dated. The IC Pyramids has a 70s feel.
The LeMeridien is closer to the pyramids. However, I don't suggest walking to the pyramids from either hotel. They are both next to a busy highway. I do suggest taking an individual guided tour to the pyramids, anyway: Vendors won't be annoying you with camel rides, photos, "authentic papyrus", etc.
Royal Ambassadors are treated very, very well at IC. Upgrade to duplex suites (also very dated) with great amenities (daily fruits, appetizers, cheese, deserts, chocolates, and one wine bottle brought to room). The IC has a great, big swimming pool. The Concierge organized a wonderful pyramids tour on short notice with a great guide.

For Cairo downton, the IC is definetly the better choice. Stayed at the Sheraton twice. They twice did not recognize me being platinum.
IC will give you at least a one-bedroom suite, as RA.

Heliopolis (LeMeridien, IC Citystars) is close to Cairo airport, but quite a bit away from downtown Cairo. During rush hour, it might take 60 mins or longer to get to Cairo. Heliopolis is very far away from Giza and the pyramids. During rush hour, between 60 and 90 minutes drive, at night 40 minutes.