The Honest, The Liars and the Complimentary

I have adopted, of late, a habit that I'm sure I share with many men and women here.When I have the privilege or good fortune to enjoy casual sex with a newly made friend, I like to - after the festivities have come to a satisfactory conclusion - ask my partner(s) if they have any questions, comments or suggestions. I am not adverse, afterall, to being told my flaws and striving to work on them, or learning of any positive qualities that I may want to highlight next time.However, I've come across a reoccurring problem and one I am struggling to overcome. Friendliness and bias. It is a tendency that the sort of people I play with, are also the sort of people who don't want to hurt others feelings. In place of the brutally honest critique I was hoping for, I too often get an 'Oh, you were great'. I know it is not simply attempts to shirk the subject, but I can not for the life of me figure out how to convince them to be painfully direct and honest.How do RHPers ensure they get an honest answer to a direct question when it comes to discussing your sexual performance? Are you the type of person who would honey coat their answers to keep from hurting feelings?