Barenboim or Buchbinder, that is the question.
Well, the bad news first: None is perfect.
The Barenboim disc (PCM 5.1) has the wider sound stage. You sit in the front row and the piano is emphasized here. But the orchestra is arranged unconventional. The celli are next to the violins and the double bases behind the two on the left. Violas on the right. So you don't get that clean violin sound from the left, it's often “muddied” by the lower frequency string instruments next and behind them and the right side sounds kind of bland, stringwise.
The Buchbinder disc (DTS-HD 5.0) has the more conventional orchestra set-up with the celli and double bases more on the right side, which I prefer. But the sound stage is not that wide and it sounds more like you sit in row 8. The piano seems more in line with the orchestra and is not as emphasized as on the Barenboim disc.
As far as the playing is concerned, I prefer Buchbinder, but that could just be the result of the orchestra set-up.
Picture is fine in both cases and the top menu doesn't let you chose a specific concert right from the start on either disc.
So either conventional from a bit of a distance or unconventional up close.
Still, for about 30 Dollars per disc for 5 concerts in HD, quite a bargain.