Not only is it personal, but somehow, never satisfactory! I've got two Lowepro backbacks, including the larger slingbag + the large Lowepro hip holster and 2 attached lens cases... But what I use the most when actually shooting is a very old "banana" bag (LAFUMA, not produced anymore, alas) that I can either attach around my hips or carry on a shoulder and in which my 70-400 fits nicely (I ALWAYS take it with me + wallet and passport) and I hand hold my camera thanks to a grip with my preferred prime lens of the day... The equipment I usally lug along when fully loaded and driving is 2 cameras (including vertical grip), 4 zooms, 2 flashes and 5 prime lens + tripod and monopod. On a plane its a function of destination and type of photography I think I'll be taking... Can't take all as its too heavy and bulky... In other words, I'm never satisfied...and neither will you be!