I have never tried the Nevegal, but did go through a set of Small blocks. I ran the 2.35 up front and 2.1 in back. Superb XC tire! Slightly lacking in braking traction, but great cornering, and fast as hell!
I've also owned 2.4 Motoraptors, which were the best dry, rocky and sandy tire I've ever used. Tread design is blocky and open though, so they roll a little slow.
I know many people swear by the Fire XC's, but I've had them too, and did not find them to be a good hardpack tire. Slow, with a square profile didn't work for me. I tried Hutchinson Pythons next, and found them to be far better than the Panaracers.
My friend had Velociraptors on his Fisher, and those tires were downright scary, he said. The back tire is a decent design, but the front uses a staggered offset center tread, which causes the tire to feel shifty in some situations.
I am currently running a set of WTB Prowlers on my bike. 2.3 XT in back, and 2.5 MX up front. These tires have been amazing in every type of terrain I've ridden so far ( mostly dry and rocky ) and are supposed to be awesome on a good tacky deep woods type singletrack. These tires are heavy for general XC use, although because of their excellent tread design they belie their weight, and roll quite fast! The MX does come in a lighter 2.1 size.
Hope this helps