I have a pair of the Orvis Pack and Travel wading pants and am very happy with them. As Steve noted Orvis was supposed to release a Sonic Seam wading pant last year but it turned out the convertible wader/wading pant was such a huge seller for them they decided they didn't need a wading pant in their line. If you want a very similar pant at a price point about 1/2 of the Simms G3 look at the Redington Sonic Dry pant. I have their waders and have absolutely no complaints about them after several years of use.
Brian
"My father was very sure about certain matters pertaining to the universe. To him, all good things - trout as well as eternal salvation - come by grace and grace comes by art and art does not come easy." Norman Maclean, A River Runs Through It