For 2013 Norco actually has two All Mountain 650b bikes. The Sight Killer B has 140mm of travel and the Range has 160mm of travel. Being on the more "trail" oriented end of all mountain, it is no surprise that the Sight is a snappy handler that does well in all aspects of riding. It uses the FSR four bar suspension design but Norco puts their own take on it by using what they call A.dvanced R.ide T.echnology. The pivot locations are relocated a bit to increase the rearward axle path for increased square-edged bump compliance and it works. The 140mm of travel feels like 160 and the bikes geometry provides crisp handling characteristics.
In this video, Francis gives us his opinion about the Norco Sight Killer B and describes why it's his favorite.
The frame is hydroformed aluminum with very swoopy curves. The bike has a very low overall center of gravity which contributes a lot to its handling prowess and overall neutral balance (not front or rear heavy). The compact frame features very short 16.8 in chainstays and it is also low to the ground with a 13.3 in bottom bracket height. The head angle is also on the slack side, which is great for bombing downhill. Even when we switched to a 160mm front fork (which slackened the head angle even more) the handling was still responsive and not sluggish.
Here is some action video by one of our test riders who is using this bike and a 650b for his very first descent. He said he felt like a hero and he is buying one.
The Sight Killer B also climbs better than other FSR-type bikes due to the lower pivot that Norco uses in their A.R.T. version of the four bar suspension. The Sight suspension does remain more active than other designs ridden in our comparison, which may or may not be to your liking. But if you are the kind that likes to stand up and mash, you'll want to be sure you turn on the rear shock's climbing mode.