Excellent waders and tough...but I find the fit around my calves a little tight. I used to bike a lot and did a lot of physical sports when I was younger, so I have thicker calves. I used to have a pair of the classic guides, and that fit me better. Don't know how the G4 fits.
Then again...the G3 might fit you perfectly. Only way to find out is to try them. Performance-wise, Simms Gore-tex has always been my choice.