It's pretty simple, imo. Go to the site and make some "practice runs" before making your real reservations. Make sure you complete the checkout process! I'm thinking one might forget that if you are making several reservations in one session.
You can add food allergy notations on your reservation when you make it. And after the reservation is completed, you can add a celebration to it as well.
A big drawback that I've noticed -- at least for me, maybe I'm just not seeing it -- is a SHOPPING CART icon or link. You can make more than one ADR in a session and they're collected in your cart until you finish the checkout process. But if you're on the main dining page I see nothing that indicates you have "unfinished business." Maybe it's just me being blind or because I had one ressie and completed the checkout today. Dunno.
We booked CRT this morning (yay!!) and something that annoyed me is that your confirmation does not give a breakdown of the costs (adult vs child). I only saw it pre-checkout and didn't think to take note of the amounts since I thought it would be broken down (CRT is prepay in full). There are 4 families represented in our ressie so even though I paid up front today, they all are paying me, so a breakdown would have been convenient. I had to go back and make a dummy reservation (not checking out) to get the prices and tax/gratuity to come up.