Yup, I have less snags when tight line nymphing and my hookup percentage appears at least to me to be greater using the jig hooks. Especially when using them as my point fly.
You can tie any nymph pattern on them if you want, but I stick to the standard "tie in the round" patterns such as the Frenchie and other Czech style jig nymphs.
With regards to the JS2 jig hook that you show, I recently wrote a review that has not been posted on the JS site. I had high hopes when I heard that JS was going to carry a jig hook in its new JS2 hook line. However after receiving my order I was a little disappointed as these were my observations.
The hook is at least a 1x or close to a 2x hook length when compared to other nymph jig hooks and the hook sizes run 1-1 1/2 times larger than standard nymph jig hooks.
For a jig hook at the same price point as the JS2, I would prefer the Allen J100BL.