"The year of flat prices isn't a shocker, as valuation levels were rather above average a year ago."

I agree, and I agree with your predictions. The critical factors will be BVPS growth and broad stock market performance. As we know, in 2000 the S&P 500 suffered an inflection in its rate of price growth, dropping from 13%/yr price growth from 1980 to 2000 to 7%/yr from 2000 to present, and BRK's BVPS growth fell from 29%/yr during 1980-2000 to 11%/yr growth from 2000 to present. Even barring another inflection in the long term rate of BVPS and share price growth, Berkshire could still suffer a short term correction. Yesterday a Motley Fool analyst forecast a 20% decline in Berkshire's share price over the next 12 months.

My very rough guess is that BRK's long term BVPS growth rate, and stock price increase, will decline from 11%/yr to 8% or so without Buffett at the helm. I believe that Greg Abel is a good CEO, but no one is as good as Buffett.

The next 12 months is harder to predict than the next 20 years, but I'll apply my long term forecast to the next one year as well, 8% BVPS growth and 8% stock price increase. FWIW.

Worrywart