For me, the most intriguing aspect of the movie was the relationship between Robert and his little grandson. Clearly, the grandson only knows of Robert as his grandfather, and is not yet capable of comprehending who Robert really is. It would be interesting to see if the grandson's memory/love for Robert will change once he's old enough to fully realize who his grandfather really was.
Like others who have already posted, I was certainly uncomfortable at times watching the movie. Generally, I like to think of myself as an open-minded person too, and therefore I found the relationship between Robert and his grandson to be a touching statement on the beautiful innocence of children. Robert's grandson loves his grandfather for who he really is, and regardless of whether you agree or disagree with what Robert has done with his body, I think it's hard to deny the power of an innocent child who refuses to judge others. It is an innocent we all once had, and which disappears far too soon.