My dad has one and he loves it (fx45). I’ve driven it, and I can attest to that it drives GREAT for an “SUV”.
I don’t think his has really been in the shop for anything mechanically wrong, but I’m not positive. Either way, he has no complaints about it, so I’d imagine nothing major has ever gone wrong.
Careful with early models if they have CVT transmissions. I know the early Muranos (Nissan counterpart) have big problems with them. I see at least one of those come in the shop a week to re/re transmissions.
Cayenne S? To expensive to maintain and I see people switching over to the fx45 from the cayenne S all the time
MDX? meh
rx330? meh
CR-V?, etc,etc,etc, meh, meh , meh,