I max out, have since I've been working, and at one point got a plan where you could put it into individual stocks, put it all on one, and got really lucky. I would not ever seriously recommend doing that, but I am a huge advocate of 401's.
It's kind of funny, I'm 45 and have seven figures, but I still max out from habit. My company matches some, but not much.
I'll bet, though, that when I/we get to retirement age, your SS payout is going to be at least partially pegged to what you have in your own retirement accounts, not necessarily what you contributed to SS.