I own two Gitzo tripods and they have worked great for me, with no issues to date. However, I have heard a lot of complaints about Gitzo's customer service...or lack thereof when you really need it.
I have looked briefly at RRS's tripods and they ooze quality, but I have not used one yet. But what I can say about RRS is their customer service and quality control is beyond superb. When I decided to invest in a pano set-up, I wrote to RRS with a few questions and they provided me with thorough answers, gave me several options to consider, and stayed with me until I had a complete understanding and knowledge of which setup would work best for me. They truly care about their customers and they want to maximize your photography enjoyment to the maximum extent possible. RRS may have premium prices, but in exchange you get premium products and amazing customer service. Now that's the type of company I like doing business with.
Bryan