I love my GD. Tried and true. In a year I've lubed it once, and it works perfectly but I will not say "better" than other posts, just "different".
As mentioned by Endomaniac, I too like the strong return of the GD. It leaves no doubt as to the position it is in. It doesn't have infinite travel, but after riding a Crank Brothers and Command Post, I find I really like the simplicity of the GD and pre-defined travel stops. I don't have to wonder what height the post is at (one stop for one inch and two for four inches). For me less is more.
The GD is not without its detriments though. The shifting mechanism could really use some updating. Lots of throw required and the lever is huge compared to new designs. And then there is the boot question. Personally I've come to embrace, dare I say even like, the accordion boot. It's a turn off to many, but I'm over that. The many advantages of the GD out weigh these two small issues.
Bottom line, all of the posts are good designs and will improve your riding. You will quickly adapt to what ever option you choose, and likely never look back....instead you will continually ask yourself why you waited so long.