Good questions and something that I wish had been proposed to me years ago. After years of investing in a 401k, I can say that today I am not putting any money in one. Here's a quick synopsis of what happened for me. I contributed almost 10% for 6-7 years at the advice of a random person (yikes!). I didn't even know what funds, all I selected was Aggressive. I took a couple of loans against it to try and start a business, which failed.
Then in 2012 I cashed out a $90k 401k. I paid taxes out the wazoo (very weird tax year for me). I couldn't find anyone to tell me this was a good idea. It's working for me and I'll tell you why. I was underwater on my house in Atlanta (took am 80/20 loan in 2005 and 20%PMI hadn't gotten anywhere) and was trying to move out of state. I refinanced and paid $30k from the 401k to pay off the 20% PMI loan and get out from under the house. Got a new 3.75% rate on conventional 30yr, hired a property manager, and the property is now an asset. This started me on my path to REI.
At this point, I don't contribute to a 401k. I don't like being tied to equities that god knows what will look like in 30 years. Yes it's free money I'm leaving on the table, but right now it's about cash flow. I have a plan to purchase 1 SFR a year and I need everything bit of liquidity I can get. This is my plan and I expect a few paid off SFRs in 30 years to be a very good retirement.
I like control of my future and REI is the preferred vehicle for me! But if I were to invest, it'd be the bare minimum to get company match.
Best of luck!
Zach