The rounded lugs are called "fingers". They help a track bite in the heavy spring snow and on the trail while the paddles help a track work in the powder.
There are 2.52" "finger tracks and they work well 85% of the time UNLESS you are predominantly a deep powder rider. If that's the case, opt for a paddle track.
There are two tracks with paddles and fingers. They are both 3.0" pitch and require a driver change. The first is the Maverick and it's standard equipment on the 2006 and newer Yamaha mountain sleds. The problem is, on the early versions, the paddles and fingers tend to bend over and the track loses effectiveness.
The second is called the Powerclaw. It's new this season and it's single ply track and so far the reviews have been good.
Best of luck