I took my 2010 Mini on over 1 million air miles, but largely in the cockpit with me. I did however also have to ride in back and the mini fits well on narrow body(737, A320) aircraft and widebody’s but not on regional jets. The current FAA rules are that if there is room in the overhead when you board they have to let you bring it, so paying for priority boarding will help. More than that, a friendly smile and polite request works best with most crews and gate agents though.
On the other hand, we sometimes worry too much. In spite of all the horror stories out there, and I have seen some, touring musicians such as Tommy Emmanuel and Molly Tuttle routinely check their instruments and have never had trouble. If I have my Carbon fiber with me I have been known to accept a customers guitar in the cockpit(after a security check) and put mine elsewhere.
Sorry for the rant, but even though we get anxious about our instruments 1000’s are checked each day with mostly good results. We all hope not to be the exception( I was an exception with UPS….so I get it).
Get the Mini, looks good, sounds good, travels well. I only stopped bringing it to have the wider 1.75” string spacing which I prefer. I now take my 322e or a Carbon Fiber on my trips.