"If you have enough money to fund your retirement, there is no need for a buffer of cash and fixed income. You might have to sell a little stock when it's cheap sometimes, but you'll also sell some when it's expensive. Over the long run you'll get the average valuation, and get a positive real return you wouldn't get with the cash and fixed income."

You've mentioned this number of times - you discount sequence of returns risk?

Sequence of returns not an issue "If you have enough money to fund your retirement".

How much is enough? If you have to ask... ;-)

Buffett (2014): "But I've told the trustee to put 90% of it in an S&P 500 index fund and 10% in short-term governments. And the reason for the 10% in short-term governments is that if there's a terrible period in the market and she's withdrawing 3% or 4% a year you take it out of that instead of selling stocks at the wrong time. She'll do fine with that. And anybody will do fine with that. It's low-cost, it's in a bunch of wonderful businesses and it takes care of itself."

He also said "Vanguard would be fine, and Berkshire would be fine...I wouldn't want to be touting Berkshire".