If your willing to pay attention to the markets, then 401k is probably a good idea.
However, just about every 401k I have ever been in has lost money. One company I was working for, their 401k was always losing around 20% of the investments. Every quarterly report would say something like -15%, -20%, -22%. I would call the 401k management company and ask what was going on. Their usual response was "we can not give out any investment details". After moving my money to several different types of investments, and still losing money, I finally pulled everything out and closed my account.
Another company I worked for, their investment managers would lose 30%, 40% of the employees investments. When questioned, the management company would never give any details. Like one employee said, if they just bought stock in coke-a-cola or 3M they would get a nice return. But for some reason the company was bleeding money.
Even if the company was matching my 6%, if your losing 20% of your investment, your wasting your time.
The 401k I am with right now is the only one I have seen a good return on.