I have been Hertz Platinum since receiving complimentary membership upgrade from AMEX in Dec 2014. I always rent/reserve a full size without neverlost. Daily rate is usually $50 - $80 depending on location.

I have used it:
Three times in LHR - Upgraded to Volvo SUV twice and Mercedes ML once. I was met at terminal with car brought to me without having to take bus.

Twice at AMS - Upgraded to Bentley Continental GT Speed (Best upgrade so far) and then a Range Rover Evoque. They delivered car to terminal each time.

Once at SFO - Upgraded to brand new Infinity Q56 - Picked me up in Hertz Towncar and drove me to car rental center where someone was waiting to greet me and hand me keys to car.

Also rented from several other US rentals live LV, Miami, etc. without much of an upgrade or additional service above normal gold.