You can't go wrong with a Billingham bag. They cost a bit, initially, but last long enough to make it worth the cost. I have both a Hadley Large, and an Fstop f/1.4, bag. Both are actually more like medium in size. Billingham has both smaller, and larger, bags. The 335 will work as a carry-on for a regular airliner. The Hadley Small Pro, Hadley Rucksack 25, etc, may be a better fit for a small plane. The 307L, and Fstop f/1.4, are being discontinued, and are out of stock at Billingham, but may still be available at places like Adorama, B&H, etc. The S4 is a good, smaller, bag. What will you carry in your new bag? Billingham bags are: well designed, well made, durable, customizable, highly weather resistant, and padded all around. Others-Domke, for example-are often not padded on all sides. Billingham has bags small enough for one pocket sized Point & Shoot, with some batteries, and bags large enough to carry three full frame bodies, along with five,or six, lenses, and every size bag in between.....something for everyone. I have tried Domke, Lowepro, and others, over the years, before trying Billingham. Since first using Billingham, I have bought nothing but. My first Billingham is nearly 7 years old, now, and looks, and works, like it is new. I have a lot of photo gear,
and need several bags for it all. I will be buying another Billingham-a 335-as a birthday gift to myself soon. I recommend you check Billingham.co.uk, and see if you don't find something there to suit you.