I've used Simms wading boots for over 20 years. I still have my first pair of Simms Guide boots as spares.
Today my new G3 Guides arrived so I can finally toss the G4 Guides which are the worst wading boots I've ever owned from any manufacturer. Bad design, bad materials, bad build quality.
The G3 Guides look and feel great! Comfortable and seemingly hard wearing... I'll let you know in a few months.