Nikon is another that offers a good value for the dollar but they cannot compete in optical quality to the corresponing Sightron lines.
I can't speak specifically about Sightron's rifle scopes, but my experience with their spotting scopes is directly opposite. A couple of years back I was looking for a spotting scope in the $500 range, and ended up doing a side-by-side comparison in the back lot of the sporting goods store (about a 200yd open field) with among others a Sightron SII 20-60 (retail about $600 or so at the time) and a Nikon Prostaff 16 - 48 x 65 (about $450).
I was surprised at how poor the Sightron's clarity was, especially for the price. It had a fat, fuzzy, purple fringe around everything, and was somewhat dark to boot. It was so bad I thought for sure it was a bad scope (display model after all...) so I had them bring out an unopened scope, and it was just as bad. The Nikon was very crisp, clear, and bright - it was so much better than all of the other brands I had to compare that it came home with me instead of a Leopold, Burris, Bushnell or Sightron.
I'm just sayin'
Just a Shooter