Ive used SIXT a buncha times, always competitive rates and seem to have a much sleeker/newer fleet. When I used in airport I was disappointed with customer service (though I was given sweet low mileage Volvos both times) but the downtown NYC location has on both locations I used it, been fantastic. Super busy so a very long wait, yes, but not bec of the staff, just bec of demand.

I was upgraded from a premium small car to a nice new s60 the first time, and second go round they upgraded me to an X1 from a regular SUV rental. I always check out their rates when Im renting now in NYC area, shame its such an inconvenient city location.