I have the GT3541XLS, and I am very satisfied with it (so far, only used it for a couple of months, don't know if it is going to wear down or something :-) ).
I relatively often need the height, especially on uneven ground. Compared to a typical center column tripod it is higher and more stable, and actually lighter in many cases since a center column does weigh some. In normal use on even ground I need only 2,5 or only 2 sections extended, rendering a very stable tripod.
The only drawback is the folded length is a bit longer than others, but I can live with that. I don't think those extra 2-3 inches makes much difference. On short hikes I carry the tripod in my hand, on longer ones I have it attached to the outside of my backpack.
Oh well, not having a center column is a drawback in some cases of course, when you have very close foreground so you need to micro-adjust height a center column is nice. If I shoot flowers or other close range stuff I prefer a tripod that has a center column.