Main Criteria:
1 - Durable, want this to last for many trips over next 10-15 years.
Check, mine are 20 years old
2 - Must be within airline size limits, adding up all LxWxD must be 62" or under
Check
3 - Must be waterproof itself or have a easily packable rain cover for it
Check, they even float and completely water sealed.
4 - Prefer it to have wheels
Check
5- Looking for more soft sided, not after a 4 wheel spinner hard case
You will never want a soft case when you can use one as a chair in a busy airport
I am a HUGE fan of the Pelican cases, I have had mine for many many years and they have traveled around the world and to Africa 50 plus times. Even though I simply use them as luggage they get the special treatment and always hand delivered to me as most baggage handlers assume their is equipment in them. They are super tough, I mean indestructible!
I always get questions about them and I can name at least 20 people who have bought them after joining me on safari and seeing how indestructible they are. They make handy seats as well when nothing is available at those busy airports ,,
The only downfall is their empty weight of 15 pounds without the interior bracing. However Pelican now makes an airport travel case specifically for flying that is lighter.
Oh, One more thing, I have glued into the cases Airtags and can track them anywhere I go, they were lost in healthrow in June of this year and I was able to tell the airport person exactly where they were.