I have had bad experiences with nearly all of the above services. I have been using a smaller one for the last year or two called Allen (212-228-1111). They were late only one time of about 30, and the cars are always in good shape. Same fares as the majors ($45-ish to JFK). My only complaint is that the telephone reservation staff can be a bit surly, but the drivers were always pleasant.

As for the others, Allstate's cars were practically duct-taped together. Carmel was habitually late, and Tel-Aviv had some of the problems of each of the other two. (If I had to choose among them, my vote goes to Tel-Aviv.)