Seeing as the GT1 class is so much faster they shouldn't have a problem with overtaking off the racing line, slowing down further in a GT2 car is not a good idea since its already so much slower.
I'll leave as much room as possible when being overtaken, but I'd also appreciate the courtesy of being left room in corners and not being pushed off the track by a faster car on a corner. Being 9 seconds a lap quicker on such a short track means there's going to be plenty of lapping, let's not have a repeat of last rounds events.