I travelled for 3 months with my gorillapod SLR and ballhead supporting my 5D2 and 28mm sigma which is a pretty heavy combo, and while it may have struggled slightly in certain situations and did eventually break, I was happy with how it as a solution to my needs. The newer models have metal ball joints which should mean that they won't break like the old plastic ones did.
IMHO, a much better choice would be a bean-bag. You can make them yourself (cloth, sewing needle, thread and lentils) or you can buy a pre-made bean-bag with a 1/4 tripod-screw. It will support just about any weight - and like the gorillapod, you still need something to use as support.
I bought a Gorillapod Focus last year. It comes everywhere with me now. It never ceases to amaze me in the scenarios I have used it. Here's an example of it in action in an area where no self respecting person would carry a large tripod. Strapped to a scaff pole 75 meters above the ground on the second largest tower of an oil refinery. That's a 75m climb up a caged ladder to get there.
It is quite versatile, and much lighter and more mobile than most tripods.
used mine for the first time today, not overly impressed but maybe i wasn't putting it to it's best use, will try again soon. i have to say i'm impressed with it's portability tho, it fits right into my camera bag (have to bend the legs up that's all) so 10/10 for that.
What you not impressed with? You have to remember what it is designed to do, and that is to go where your tripod wouldn't, and to strap to things your tripod can't. If you're after a rock solid support for your camera then the Gorillapod is not what you're after.
As a matter of interest do you have the ballhead on yours? I first bought mine without a ballhead but I found it impossible to get the camera straight while strapping the gorillapod to something.