I use the Gitzo leveling base with the same tripod. I also have the Gitzo Explorer, the first generation carbon fiber tripod that I used with everything until I got a 500mm F4, which is when I added the Gitzo 1548. Now, unless I'm going specifically for macros in a flower garden, I use the 1548 and the leveler for all my shooting.
I am 70 years old, but find the tripod, leveler, my 1DMkII and whatever lens are easy to carry on my shoulder, with the help of a foam pad. The weight is more than the Explorer, but the added stability and usefulness of the leveler makes the combo a winner.