With the trailblazer being a 2 stroke 250cc and the 300 ex being a 4 strock. Which is faster.. You would think the Polaris, but I am hearing people with 300ex's are blowing away these trailbalzers? I need you input.

a 300 ex with a pipe,air filter, and jet kit would blow a stock trail blazer away.

Yes, the 300 will beat a TB. I would not say it will blow it away, but it is faster.
The 300 is tuned a little more for sport riding. The Blazer is more of a recreational quad.
But on the other hand, you can add lots of power to the Blazer with hop up parts to make it faster.
Also, the Blazer weighs considerably more then the 300.

Depends on what you mean by "blow away"

On a straight flat road the ex will pull ahead (gears verses auto) and has faster top speed.

Put both stock on a track with woops and berms and jumps and all bets are off - now it depends on the rider - I smoke banshees on small mx tracks with my wifes stock TB only because I ride crazier than the banshee rider, now find a crazier rider than me and the banshee will smoke me or another tBlazer for that matter.

It's all relative :)

in stock form i would give the edge to the 300EX, in a straight line race, but add in terrain and driver skill and it is hard to say. Put me on a Trail Blazer having 17 years or riding experience several on a Yamaha Warrior and I am sure I would give any 300 EX a run for its money on the trails. but add a pipe to TB and in a drag the TB would beat the 300Ex even if you piped the 300 why? well most of us know you do not get the huge gains from a 4 stroke you do when adding a pipe to a two stroke and from what I have seen the TB really comes to life with a good pipe on it.