I'd like to suggest this alternative
to all those people who are talked about for being "brutally honest" and "painfully straightforward". These tactless people will supposedly tell you exactly
what they think
of you with no regard for embarrassment
or social position.
What I've noticed is that these people are usually only negatively honest. They will easily tell you how ugly you are or you have spinach in your teeth or you're arrogant or that you can't write to save your life. However, when it comes to telling you positive things about yourself, they seem to close up and shut up. Have you ever heard some brutally honest person say, "you know, I think you look absolutely beautiful today"?
If you insist on being brutally honest and straightforward, try going both ways. Be tactlessly positive.