When I had the 335d Coupe that I was rented in place of my 330d initially I felt very guilty about it all.
However when the 3rd party's insurers made no attempt to inspect my car for weeks I got increasingly frustrated by their lack of action. So in the end I felt no guilt at all about having the car for 7 weeks. If they could not get their arse into gear and get my car inspected why should I have had to drive around in a shitbox for that length of time?
Accident Exchange were also very helpful in terms of their advice and assistance in the settlement negotiation.
So despite the fact that I dislike sharks exploiting this sort of situation I would have no hesitation in using a company like this again.
However thier rental prices, despite being hideously expensive, don't seem to be quite as bad as these folks who rented you the TT.