More pros to the R8 and Blaser rifles in general:
You can carry the rifle totally uncocked (no compressed firing pin spring) with a round in the chamber. This is because the "safety" on Blasers is the cocking lever. In other words, when you slide the safety lever to the "off" position, you are cocking the firing pin. This means that "flicking off the safety" requires more travel and a little more resistance than is typical with most rifles, so I guess that could be considered a con.
Blaser triggers are fantastic...very crisp and fairly light.
Their saddle scope mount system with the QD levers is nicely designed and provides spot on return to zero after dismounting and remounting. They take down to a fairly compact package and fit into a small case that doesn't look like it contains a rifle.
You can get some really nice wood in the wood stocked versions, but at a price premium.
You can get quite a few custom options, if you're willing to pay for it. Again, it can get pretty expensive!
As stated, the main con with any Blaser rifle -- and it's a pretty significant con -- is they are very expensive.
Disclaimer: I don't own a Blaser R8, but I do own a Blaser K95. It's a beautifully made, elegant rifle that really shoots. I love it!