ECM released all their PM stuff in Japan on gold and regular CDs. Both series were limited edition in mini-lp sleeves. More recently, a few PM CDs were released in the "Jazz the Best" series at lower price than the ECM. Again, a few were gold and others were regular CDs. The ECM series go for more in the secondary market.
I personally like the Metheny/Mehldau CDs, but I prefer the quartet pieces over the guitar and piano pieces. I also like most of the others previously mentioned as well as "The Way Up". The only thing I really dislike is the guitar synth. For me, a little goes a long way.
BTW: You should enjoy the "White Album", it's a must have.