Even Jet Blue allows a bunch of titles. Problem is for example if you have a BA ticket and then fly AA - the boarding pass will read something like "Flying Sir Geek" and on one occasion the TSA rep had no idea what it was and didn't want to let me through since the name didn't match and I only had a US driver's license with me. Took a supervisor to let me through - and my joke that I left my shining armor at home to make it easier at security was clearly not deemed funny.
To answer the OPs question - I do not believe you get any different treatment. Granted I am no Lord or anything fancy - and if I book it myself I would always slect Mr. On the few occasions someone entered the title, 99% of the time you wouldn't even be called by it. You are Mr Geek instead of Sir Flying.

Let's hope someone plants the trees