If you're comparing standard rooms and not considering suites, I'd go with Fairfield because the rooms have a foldout chair that can sleep the 5th person (child-sized).
We're a family of 5, with my youngest being 4 and oldest 10. We've stayed at HoJo the last two years and there's been plenty of room, even with the rollaway bed in the room. Can't say anything about Fairfield. Never been.
We are a family of 5. I would always pick HOJO over Fairfield. Both are good, but HOJO felt like the rooms were bigger. We also like the water play area for the kids.
We are a family of 5 and we always stay at the Anaheim Marriott Suites. We get one bedroom usually between $70-90/night and the extra space is more than worth the drive to the parks each day.
If you have the option of the Kids Suites at the HOJO then hands down pick that - they are the BEST! We love the two rooms, two bathrooms, two closets, lots of room to unpack your clothes, two tvs. So much space and so great for a great Disneyland holiday. We only had a party of 5 once when my MIL stayed with us, the pull out sofa was not the greatest but a $20 mattress pad from Walmart made it wonderful!