I stayed there with my sister in 2009 for two nights. I booked it because I got a great rate of $49 a night.
The hotel was fine. The rooms weren't modern (old TV set, dated bedding, etc.) but it wasn't dirty or uncomfortable by any means. The room did have a mini-fridge but no microwave.
We didn't eat at the restaurant in the hotel nor did we use the pool, too cold, so I can't comment on those.
The only downside really was the cost of parking. Parking is $12 a day. We (foolishly) thought that we could walk, but in the end, it was just too, too far. It is more than a mile each way (using mapmyrun.com). The Clarion is, however, right across from the Toy Story parking lot, so I'm guessing you might be able to take the
Disneyland bus to the parks, though I haven't done that personally.