The 1510 [1514 with the divider set] is the size of the largest carry on bags allowed by the FAA. And it's no problem to gate check it if on a small plane as it can be tossed around without worry. You can read more about this case at Adorama here.
The case I acquired did not have all of the divider sections but I was able to find a used set on Amazon. After playing around with different configurations, I was able to fit almost everything I carried in my Tamrac Ultra Pro 13 and more than I could fit in my thinkTANK Photo Streetwalker Pro backpack.
One drawback is the weight. The case alone weighs a touch over 15 pounds. Filled with gear, the case weighs in at 33 pounds. Definitely a storage solution rather than something you'd lug around on a hike. Without a doubt, gear will be transferred to another bag for almost every shooting occasion.
Here is an iPhone photo of how I finally managed to set up the case with my gear. I'll list the contents of each compartment in clockwise order beginning in the lower right with the camera bodies.
|Pelican 1510 case with padded dividers  with 1519 lid organizer|
Canon EOS 7D with battery grip and two batteries, OP/TECH pro loop connectors.
Canon EOS 7D with battery, OP/TECH pro loop connectors.
Canon 430EXII and 270EXII Speedlites, lens shades for 70-200mm and 24-70mm lenses, Canon 500D 77mm close up lens in case, Rocket blower.
Sigma 10mm f/2.8 fisheye lens, 16 Eneloop AA batteries in Tamrac battery case, business cards.
Canon EF 70-200mm f/2.8L IS II USM lens, OP/TECH Utility Straps (2).
Hoya Digital Pro 1 CPL and UV filters (77mm), Tiffen 3 stop ND filter (77mm).
Canon EF-S 60mm f/2.8 Macro USM lens and Canon Extender EF 1.4X II connected with OP/TECH double lens mount cap.
Canon EF 24-70mm f/2.8L USM lens.
In the lid organizer starting with the top left are:
Jar opener for filters, extra CF cards, lens mount caps, anti-fog eyepiece.
Spare LP-E6 battery, AA magazine for battery grip, Bower 52mm to 77mm filter adapter, swab and cloth for anti-fog eyepiece.
Zeiss lens wipes (for filters and LCD screens), Microfiber cloth, OP/TECH Gotcha wrist strap.
Canon Remote Switch RS-80N3, Canon flashlight, self defense spray.
In addition, I lay a Rogue FlashBender (large) and Bounce Card/Flag on top of the lefthand portion of the dividers.
UPDATE - 6/13/14: The only refinements I've made so far is to switch from the OP/TECH straps to the original Canon straps to save space and I keep my 40mm pancake lens on the 7D body without the battery grip.