As you know, Warren Buffett was scaring me with Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B) selling airlines (almost at any price), banks, and raising debt when he was sitting on a stack of cash anyway. So much so, that I sold my Berkshire shares and bought Pershing Square (PSH) which was trading at a 30% discount to assets and had a large investment in Berkshire.

Here is an explanation of why I switched to Bill Akerman's Pershing Square
Pershing has since sold its stake in Berkshire

and while I am still happy with my investment in Pershing Square Holdings, Ltd. (LN:PSH) (LN:PSHD) (NA:PSH) as it has risen 28% in price since I bought it, yet it remains at a 30% discount to it underlying asset value
I really want to maintain my exposure to Berkshire Hathaway, so I am buying back in. By luck, Berkshire's share price has fallen since I sold - so I am buying in at a lower cost base.
Not investment advice
As always, this is not investment advice. Do your own research. Consult your professional advisors.