Good question. Glad you asked because every situation IS different. For me, I'm always overweight Berkshire but not quite as overweight as I was a decade ago. LT gains have been a source of consumption. As I've written previously-that's about me-- not BRK.

So, much of what I don't have in Berkshire along with ultra safe short fixed income--I've had in stock index funds. It's a rare time when I feel the indexes are just so way overvalued they should be trimmed--but I've trimmed them recently. So in my LT Berkshire/Index "balance" I've lightened up on the Index recently and I see Berkshire as substantially more attractive and it's not even close. It's not a trade its a small amount of cash intended for the long term-reallocated. Wasn't planning on adding to Berkshire but Berkshire came to me :)

I don't make this move lightly. Re: the Index recently: Don't believe in cutting the rose at the stem per Lynch. So, I had money freed up and, yeah, I'm overweight even more Berkshire to your point.

But on this topic-- Buffett cites Mae West "Too much of a good thing is....wonderful".