Hi Everyone,
First of all, I want to thank you all for the awesome portion of knowledge you can get from this place. I've been reading this forum for quite some time already and must say it's one of the best places about wildlife and generally about photo gear. I've learned a lot thanks to all the content you post here. Time to start be more active member
I'm looking into the Nya Evo 60l pack and I couldn't find any photos or description how much free space is left for other things when you pack it full with RCI XL. I saw great photos showing the fitting the combo with 600 TC. From what I understand the main compartment is full and on the top you won't put anything else unless you expand the rolltop (but that wouldn't be good in airplane - dimensions). What about the front panel? How much you can pack there when RCI XL is inside (full with gear)? Can you add some 1-2 day clothes, jacket, raincoat, some basic stuff, cabling, laptop or you don't have any available space at all?
So basically to pack everything, go with this as carry on and be able to survive 2 days if airlines loose your checked luggage

Of course ignoring the weight of 20kg