Bar, Doesn't that Apple position represent something like 25% of Berkshire? Not very prudent in my book. Apple is a great company, but it could be that Buffett is taking such an outsize risk in an attempt to reverse Berkshire's under-performance - it's been lagging the S+P 500 for a long time. He's also having trouble finding suitable new investments, valuation-wise. But 25% in one company seems too risky.
There a decent chance Berkshire will be broken up after Buffett finally departs. Face it, as a conglomerate it's not the most efficient business model these days, though Berkshire does have the advantage of being able to supply funding to its group of companies when needed.
United Technologies may have the right idea, to spin off the disparate businesses while retaining a sizable degree of ownership. Seeing what happened to GE, they decided to get ahead of the curve.
