I think Hertz has a better Luxury fleet, especially given the Prestige collection. With that said, I am EE with National too and the the nicest Luxury car (actually in Luxury class) is the Caddy XTS. I've had several ATS, but you have to make sure it's the 2.0 turbo and not the smaller engine. hertz has the ATS in both the turbo and a larger 3.6L which National does not from what I've seen. Upgrade cars are a lot more plentiful with Hertz.