As with Pete above we stay a tad under half the year here (please note Mr taxman
) and we have now got our own vehicle after years of hiring.
We always used Firefly, good prices out of Peak season but "ouch" during peak . . always very good treatment and no problems tho, avoided Goldcar like the plague!!
Even though we never had any problems with Firefly, there was always that nagging in the back of our minds if you were going to be turned over, plus often longish queues on arrival.
We got a brand new car so no ITV issues for 4 years, 3 years "proper" warranty and no dodgy history. The Insurance is reasonable and includes breakdown cover and covers any driver so family are covered too, servicing around €100 per year at main dealers.
Its a moot point if its really any cheaper but for convenience and peace of mind I think its worth it.