Where did you get the notion that he wants to use a backpack "just because other people do"? He specifically says he is coming around to the idea that they are more practical than the more traditional alternatives.
I have a couple of questions:
1.) Does one need to "sign up" for this meetup for the purpose of a headcount?
2.) Is this meetup restricted to men? I have no plans to show up accompanied, so my question is just a matter of curiosity.
I have the straight leg model. I'm not sure what I can tell you beyond what is contained in the description on the website, other than the fact that I find them extremely sharp-looking and comfortable.
This isn't going to be the response you want, but I think you're over-thinking the issue. From what you describe, your personal style already sounds pretty consistent to me and my guess is that you're essentially the only person who perceives (or cares about) any lack of consistency.