Simms does a couple things really well, that's waders and boots. I bought these for my dad and have a couple of guiding buddies who have worn these boots also and not too many complaints.

The Boa lace system is really great and super easy to use. The Vibram soles that come with Simms Boots are also really comfortabel and easy on the environment with how quickly they dry. Moreover, the bottom of these boots are designed to easily insert and detach studs for extra grip.
The synthetic material also withstands all the different elements you will encounter while out on the stream and will keep you looking fly while drifting some #20 Griffith's gnats to noses on the upper Roaring Fork.

Only complaint I have recieved from these boots is that the BOA system will eventually break on you, and if you are fishing/ guiding close to 200 days a year these laces are only going to last you a season. Once they break you can buy a new replacement system, but it wont be as cheap as buying a pair of regular laces.

These boots are great the one downfall is just that the BOA laces may fail on you after they have reached their life. However, if you are fishing around 50 days a year these are going to be the boots for you with how well they fit, grip, and lace up in an instant

These are a significant upgrade from my first wading boots. The boa is convenient and easier to use with gloves on. The ankles are also more supportive than other boots, so walking on uneven stream beds is much easier now. In sub-freezing temperatures, my feet also stayed warm enough to last a full day (which had been a problem in the past). I ordered the 9 and there is room for my 8.5 foot with waders.

I bought these for my teenage son and he loves them, the quality and durability you come to expect from Simms with the easy lace up and lace off Boa system makes these a go to. My son loves the fit and ease of getting in and out of his boots.

The Boa was the selling point on these, I have ski boots and cycling shoes that also use the boa. Cinches tight. Legit!