I have recently come to love the piano concerto by Salonen's classmate Magnus Lindberg, who I personally think is who Salonen would have turned out to be, had he focused more on his composition from the beginning, or had he not got his gig in Los Angeles (which, sadly, comes to an end this summer). Lindberg's piano concerto has a lot of similarities to Salonen's piano concerto, but takes a much more no-holds-barred approach, much like Salonen's early work. It never treats the piano as a percussion instrument, but rather as a very resonant and colorful instrument, almost in an impressionistic fashion (the piece in no way sounds impressionist though). It is definitely something to behold. Also, Lindberg himself is a well accomplished pianist (and recorded the concerto), so there aren't any unabashedly unpianistic parts, which the Salonen concerto is full of (my view of the score confirmed my thoughts on its unpianistic-ness).