Just a general follow up to the RRS series 3 vs Gitzo series 3 discussion.
Originally RRS was going after the Gitzo 5 series market with the RRS series 3. The Gitzo series 3 states that it's ideal for lenses up to 400mm. The RRS series 3 states in their catalog that it's ideal for the 600mm lens.
Technically according to Gitzo, the Gitzo 5 series is for the 500mm, 600mm, and 800mm lenses. Now, I would certainly agree that the Gitzo series 3 does work well at focal ranges from 500mm to 1000mm. However, Gitzo doesn't promote it that way. So when you compare the specs keep that in mind.
You should really compare the RRS series 3 with the Gitzo series 5 and when you do that then you will see what an accomplishment the RRS series 3 is. Series 3 of one company does not necessarily equate with series 3 of another company.
Also, weight capacity doesn't necessarily translate to stability at longer focal length's. Stability should really be tested separately from weight capacity.
I should also mention that I own the Carbon Gitzo systematic series 3, the 4 leg standard version, which I love by the way. When I bought my Gitzo tripod about 3 years ago, the RRS tripods were severely back ordered and I was hesitant to buy a tripod unseen and untested, so I went with the Gitzo gold standard and I don't have any regrets.
However, if I were buying today I would probably choose the RRS series 3, because I have been so impressed with the quality products that RRS continues to churn out, as well as the interoperability that they offer amongst their own products. Personally, I also find it nice dealing with a local USA company for the convenience if any problems should arise.