We went to Elveden Forest when DD was little with my sister, her DH and DD, out of school holidays in November, and really enjoyed it.
However - restaurants - hugely overpriced except for the posh revolving one, which was great but only for a treat, couldn't possibly afford to eat there every night!
Comfort plus (hate to think what Comfort on its own was like) was a damp, concrete bunker (DH christened it The Gulag) that stank of damp in the kids room, so we had DD in bed with us all week, which was nice...They promised to bring in a dehumidifier but it never materialised.
Activities horribly overpriced for what they were, horse drawn carriage ride (kids too young for actual riding) an absolute rip off, couldn't believe they had the nerve to charge for what was basically a trundle up one path through a load of chalets and back down another path through a load of chalets...
Mini disco was excellent fun, the kids loved it, the other child-related activites were good but really not worth the money. Outdoor play areas fantastic, the kids loved them. Nursery was excellent, as was the babysitting service, which we used one night.
Pool was wonderful, would go again just for that, it was brilliant, as was the Spa. I could have lived in the Spa!
We went to Butlins the year after and for half the cost were in an apartment that was 100% bigger, brighter and better, and all the attractions were free, so on a value for money basis I'd go for Butlins every time - however, Butlins pool was freezing and I've never seen so many obese families chain-smoking over pushchairs in my life, so I guess you pays your money and takes your chances...