I used Enterprise to ferry some senior colleagues around a couple of clients recently. All very good except they upgraded me "free of charge" from a Mini MPV to Full MPV and then tried to charge me full whack for the higher class vehicle when I returned it.
It was (eventually) easily explained away: "apologies, our mistake, I see what you originally ordered now", but took quite a bit of time and 'discussion' to resolve, and unfortunately left a bitter taste in my mouth.
Other than that, the staff and service were great, no attempts to push silly insurance or other added costs.