In MSG2 Raiden was naive, green, and had none of the calm efficiency of Snake. By MSG4 he'd been turned into, basically, a killing machine. And that's what he did. He ruined those GEKKOs pretty handily and I think Kojima's and Platinum's goal was to put players in Raiden from MSG4 shoes.

I haven't played the game yet, myself, simply because I just haven't taken the time to go get it, but I'm certainly looking forward to the game. And while you can go gonzo as Snake in the other MGS games, it never felt "right", as you hint at. Whenever I ended up causing an alert and had to shoot my way out of trouble, I always felt like I had betrayed Snake's sneaking ethos, even if I silently murdered guards behind a convenient bush or wall.

Now that we get to control cyborg ninja Raiden, I think a gleeful bit of the old ultraviolence will be a fun change.