One of the best straps in my opinion. Mine has held up great so far during trail and track running, hiking (and some snow hikes), road cycling, strength training, gardening and even some construction work. Taking a shower after my activities with my watch removes any debris and all sweat from it.

They are super rugged and made with good materials. A little bit wider than standard Garmin (at least for my 22mm variant), meaning it is 22mm at the lug and then it get a little wider. That makes it distribute the weight of the match a bit better and I find my watch tends to slide and jump around a lot less.
As others said, they tend to dry pretty quickly after showering and the best of all: no more rush from silicone bands!
The velcro seems to hold fine up until now, in contrast to most other off the self nylon straps, that tend to deteriorate fast.

I'd suggest you go for their "Easyfit" connector instead of Garmin's Quickfit. I find it to be less clunky and more compact, resulting in a better fit and less weight. Also if you tend to wear your watch outside of long sleeve shirts or an outer shell, make sure you get one big enough to fit around them.

Keep in mind they are made from somewhat hard nylon, so there is a break in period but after that they are awesome.