If OP takes the CDG VAL to the Roissypole stop, the Hilton and the newer M hotel are both possibilities.
Hilton has an atrium dining room with better food than I have found at the airport. The best deal is the daily special which is three courses for 23-25€.
I walked through the M's public areas last fall. The hotel itself is a mid-range property with a social club theme, aimed at a younger crowd-let's have a sandwich in the library, etc. Walking through at dinner, I saw a salad buffet and two or three entree items in crock pot type heaters. The entrees were serve yourself (and looked like all you can eat) and were the type of dish that would stand uo well being left heated for a time like that. Not too expensive and looked pretty appealing, and the next time we are at the Hilton, we may walk across to M and try it out.
Good to know someone likes the buffet at the Hyatt, as we'll be staying there next year. I don't know about going there on a four hour layover, since I have had almost 100% bad luck on ground shuttles at CDG. You would probably make your connection, but if you wait 15-20 minutes on each end for the shuttle, it's a lot of schlepping around for a meal.
Last edited by Mountain Trader; Jul 31, 2015 at 2:19 pm