When I first got my sami, it had a locker in the front only. open hubs, you would never notice it. Locked hubs, yes it was a little hard to turn, but nothing like people make it out to be. People made me think it would be impossable to go any where but in a straight line. You do notice it, and get used to making 5-point turns when all of your open buddies are just zoomin around the curves, but other than that, it's not bad. I think the bennies outweigh the turning problems. Let you friends sit around and cuss you when you walk right out of something they struggled forever with.
And as far as your going to start breaking things in the front with a locker...it's all in how you drive it. I have never broken anything in the front and I'm not exactly easy on my rig. BUT, I do know when to lay off of it and call for help on things.
If I could only lock the front or the rear, I would lock the rear first cuz to be honest with you, it is really hard to turn on the pavement with the front hubs locked in.