No experience with the AK but have traveled extensively with a Peli 1510 & a Les Paul in a soft case. Flown KLM, Etihad, Emeriates etc & rarely had an issue.
Sometimes on small aircraft I’ve had to check at the boarding gate but then it sits on top of regular luggage.
After a while you get to know the overhead bin sizes so quite often we’d just tear off the tags on the bus & take the cases on the aircraft anyway.

Cased weight might be your only problem. I’d aim for 10kg if possible, a bit of a push I know, certainly don’t exceed 15kg.

Getting your air miles up for Gold/Platinum status helps massively as you get priority boarding along with business class. Lounges are a blessing too on long connections!