I have the GT5541SGT and I LOVE it ... this has been a significant upgrade for me even from my GT5540LS just because of the extra versatility of the longer legs and improved rigidity when most of the CF is still collapsed at normal shooting heights. Now it was damned expensive and tricky to find one in stock but it impressed me even the first time I took it out. I used to find the 5540LS was very stable and great with a wimberley head on it but not so ideal for more general use where the weight/mass vs utility wasn't so ideal. The 25xx & 35xx legs are great for lighter weight use but just can't compete with the 5541SGT in terms of a rock solid platform.
Sorry I realize that this isn't helping with finding an alternative tripod to the Gitzo but I'd now consider getting rid of my other large tripods (GT5540LS, GT3531S, GT2531) and sticking with this behemoth. It's THAT good IMHO. :thumbs: