I've had nothing but exceptional experience with Simms customer service. For waders, I've had everything from Reddington Neoprene, Cabelas Breathables, Orvis Breathables, and now Simms. By far Simms have been the best for me. I'm exceptionally hard on my waders due to the nature of some of the streams I fish. I'm brush busting, crossing barbed wire fences and occasionally tripping over it when walking. You'd be amazed at how much of that stuff is in the Midwest. Wisconsin is America's Dairyland after all.
I've had my Simms G3's since 2007. I've fished my butt off in them from PA, MI, WI, CA, CO and they are bulletproof. A lot of my trips are 10 day trips - in them every day for 10-14 hours depending on the time of year and the amount of sunlight available to fish. I had one problem with them, on the protective layer of neoprene on one of the bootfoots. It started coming loose - mainly because I pull on that part to try and get the boot foot off when I have two pair of thick socks when steelhead and salmon fishing. I took them to my shop and they sent them back. Simms replaced the bootfoots, gravel guards and repaired numerous pin holes and seem items I didn't know I had (I wasn't getting wet). Free of charge.
I purchased another pair of G3's to use while they were at repair for a couple of weeks, as I had a trip planned. Love them too. Now I rotate them when I'm on a long trip.
Always turn your waders inside out to dry the inside on long trips. That sweat on the inside is not good. The outside may be wet in the morning around the neoprene, but inside will be perfect.
As for other Simms products, I've had them replace bags when zippers failed, replace wading boots when I've had a problem with them, zingers on jackets replaced. All free of charge.
I firmly stand behind this company. They have been nothing but an exceptional service firm with outstanding products - their waders are top notch.