I took a short hiatus from investing in a company provided 401k. During this time I saved up some money to put into leveraged real estate rental properties.
Over those years, the returns on my stocks have out weighed the returns on the properties (even considering the leveraged value of the RE assets).
Keep in mind, this is 2010+ where the market has done wonders.
You also have to take into account your tax rate. If you can put a few thousand away and that drops you an entire tax bracket, then why wouldn't you? If you're in a high tax bracket, why not put money away and use it when you're in a lower tax bracket (assuming we don't all get put into a 100% tax bracket at some point haha).
My plans are pretty straight forward. Try to get enough money in a 401k where I could 'comfortably' survive on a 6% interest return (anything greater would just be rolled back into the retirement account) while utilizing a different stream of cash (i.e., rental income, or other type of cashflow) for additional travel / trips / gifting money.
I currently have 4 units (2 duplexes) but want to hit the restart button and work on a different approach (more conservative and less leveraged).