When I was searching for an ideal travel tripod few months ago, I looked for one that'd have to meet all following three requirements: 1) short enough to fit inside my carry-on bag when folded; 2) very light; and 3) sturdy enough to handle decent load. After much searching, I settled on Gitzo GIGT1545T Traveler Series 1 Carbon Fiber Tripod. Its specs:
Load Capacity: 22 lb
Max Height: 60.2"
Min Height: 8.6"
Folded Height: 16.7"
Leg Sections: 4
Weight: 2.3 lb
Carbon eXact Tubes; Reverse-Folding Legs
Traveler G-Lock Leg Lock System
Paid: $599
I paired this tripod with RRS BH-30 Ball Head with Compact Lever-Release Clamp, and I was ready to travel! I gave the combo a good workout during my three-week travel to South Korea just this past month. Without having to take the head off of the tripod, I was able to fit it inside my Swissgear backpack along with my laptop on board the plane, so that's how compact it is. Once in South Korea, I had my Canon 5DIII with L bracket and 16-30L lens atop rugged Seorak Mountain terrain where it was quite windy for self-timed family photos, as well as long exposure shots in a well-shaded brook down below. Very happy with the results. It came extremely handy in a crowded room full of people celebrating my aunt's 80th birthday for a group shot, as well.
The tripod can certainly handle any gear combination that I have: 5DIII with 24-70L or 70-200L f/2.8 or with 150-600 Sigma C. It definitely meets all three requirements to my thorough satisfaction.