I've been to Chili's in Westbury twice and both times I have received good service. The place can get crowded on Saturdays but their are plenty other corporate restaraunts in the immediate area to choose from. Macaroni Grill is right next door.
The wait both times I went was 45 minutes for a table for two. The bar is small (just like all Chili's) so if you like to have a drinks while you're waiting you might have to sneak in there for a seat.
It is conveniently located off the freeway so you can get in and out of there quickly.