I agree with Mike. My preference would also be the Jewel. We love the Radiance-class ships.
And food is always very subject. One person loves Burger King, another loves McDonalds, while others hate both, and some like both.
With that said, I think the food on RCCL is a bit better - although not much and has declined over the last 10 years - mainly due to the economy and cut backs. But I feel they do have more choices.
One thing you might want to consider are the amenities. What does each ship have to offer and how do they fit into your lifestyle? You may find one ship has more of what you're looking for than the other.
But for a first cruise, I don't think you can go wrong with either one. And as aerogirl said, try one this time, then try a different one next time. That's half the fun of cruising is trying to find the one that fits you best, keeping in mind that what one person loves, another will hate. So take reviews with a grain of salt. You may find the one that gets the least amount of positive views the best one for you. Go with a positive attitude, have fun, and don't let the little things that can go wrong take away from your overall enjoyment.