There are a few discussions on this one if you dig around, but here is my take on it.
I have an X3 on my 2013 Pro 156. Major hook up. Far less track spin than stock. WAY MORE traction. Deep powder feels almost like a pump gas turbo compared to the stock 2.4 track. I'm VERY interested to see how the X3.2 works with the nubs. I'm guessing it will be better on hard pack than the X3. That's not where they are designed to operate, but you don't want to spin out and have a problem on hard pan.
I rode the 2.6 Polaris track (on the AXYS chassis) back in January. Much more hookup than the 2.4 but not the same as the X3. I'd call it a compromise.
I think it will be a GREAT track.
What kind of riding to you do mostly? Living in Boise, I'd guess your snow and riding style/conditions are similar to mine.
Some people don't like the 3" in the trees. I'm here to tell you that I LOVE it. There is a bit of a riding style adjustment, but you'll learn quickly.
AS for weight difference between the 2.4 and 2.6, I can't remember. I think I remember the 2.6 with a weight advantage.