Pros

You are tanky and hard to bring down without someone spending there Money on a Bloodrazor
your regen is massive ( to the point you see a floating number when it is active
you can push towers with out minion waves if you have a DPS or pusher with you
Mages hardly hurt if they do not get mage pen

Cons

You don't hit hard
you will be targeted as you push lanes
Ks happen when you ult
you tend to be low hp after pushing a tower and easy to bring down

In the beginning keep harassing the enemy as much as you can use Decisive strike when ever you can. I follow the rule if it move silence it. if you have a carry in lane with you pull back and let them get the kills as assists work just as well with the build because by late game you should be able to tank towers and kills most champions with DEMACIAN JUSTICE. Once level three farm minions as best as you can to get your Courage stack to max.

Hit them hard. In team fights go for the heavy hitters (mages, Nukes, and Carries) Clean up the enemies heavy hitters by starting with DECISIVE Strike, and just spin. when ever Courage and spin is off cooldown use them. Only ult when people begin to run away. By now you should at least have your force of nature and should be able to regen most of the damage by hiding in the brush.

Tank towers if the game is going well. Ignore most team fights and just push a lane.