We rented for a week in July. Some pros and cons:
Pros - GREAT location, super quiet, met some of the neighbors and they were very friendly and accommodating!! Pretty good access to water, some good bicycle and motorcycle rides in and around Isle de Madame. Everything in the house pretty much worked, water flow and hot water supply were fine. Wifi was good.
Cons: house is old with the associated issues/charms depending on how you look at them - slanting floors, short ceilings on second floor, second floor shower hit you in the chest. The hot plate on the coffeemaker didn't work so coffee got cold quickly, one shelf in the fridge was broken, some other relatively minor things like that
Other points, just as info; Water is from a well, so bring some other water to drink if that's not to your liking. Also there's no TV (which didn't bother us). There is not a gas grill, so bring charcoal if you want to cook out - the fire ring with the grate functions well for that. Mosquitoes were pretty obnoxious at night but that's just the season. The property is located on the far south end of the island so getting to anything north (Cabot Trail, Louisburg, etc.) requires a bit of a drive - about an hour, but with the scenery we didn't really mind that at all.
All that said we truly enjoyed our stay. We contacted Robert about a couple of things and he always responded very promptly.