I think that is the correct name - thought it had 'beach and tennis club'. In any case, the one I'm talking about is right across from Fashion Island.

Anyway, I stayed here a TON for work awhile back - probably close to 2 years ago, so I don't know what it looks like today as it appears from the website that a rennovation is going on, plus I think the catagory of this hotel jumped from 3 or 4 to 5.
When I stayed there I'd say the place had great positives, but some big negatives too.
Negatives: the rooms were really really old. Only one wing had fairly decent rooms, I think it was the 'tower' (south?) - the tower with the conceirge lounge. The other wing had rooms circa 1970s or something - very poor. Rugs old, closets were like 1/2 closets, etc.
Positives: location is terrific, especially if you're going for a weekend. Walking distance to a huge, and very upscale/nice, shopping mall (mall isn't a fair term for it either). I also liked the location as it's a quick drive to the beach areas. Another positive is that the hotel has a great pool. It looks like a lot of families come here, and I can see why. Also some nice tennis courts.
Basically, the hotel sorta feels like a 'this used to be an amazing property back in the day, but we haven't touched it since because we know it still sells well'. However, with a renovation going on, maybe all the negatives are gone, in which place this is a terrific hotel. I do also remember some rooms having great views of the nearby golfcourse, and then past it, the ocean.
Anyway, few other things: I can tell this is a VERY popular hotel for wedding groups to stay at - in fact, I think unlike a lot of other hotels, this hotel is busier in the weekends than the week (!).
Oh, another nice thing: they have a free shuttle from the nearby airport, and there is a Hertz counter in the hotel, so it's sometimes much cheaper to rent a car from there than the airport.

Marriott Irvine: For business/during the week stay, I think this place is great. It feels very new and I thought the rooms were really nice. But if you're with family/kids, and staying on the weekend, this wouldn't be too fun to stay at. Nothing much to walk to.