Hiya
We stayed in the holiday inn in june and are staying there this time with the kids in 19days time. It worked out cheaper, just as close, plenty of transport back and forward. You can they choose to pay at the park gate and opt for the package that suits you.
Staying at an onsite hotel is more expensive but includes park tickets so you have to work out what is best for you.
We certainly enjoyed stayin at the holiday inn and are back soon.