"I will just repeat all the praise from the other reviewers, it's a great, great set. HOWEVER, it doesn't have ALL Mozart's piano concertos---almost no sets do. Mozart "wrote" 3 concertos for harpsichord, collectively known as K. 107, which are actually arrangements of other composers' music. Perahia recorded these with piano and English Chamber Orchestra on CBS (probably Sony now) MK 39222. Also, Mozart's Piano Concerto #7 for 3 pianos K. 242, and Piano Concerto #10 for 2 pianos K. 365 are not included, but you can get Perahia playing them with Radu Lupu and the English Chamber Orchestra on Sony SK 44915. [They play the 3 piano concerto in Mozart's own arrangement for 2 pianos.] So any Mozart completist who wants the remaining concertos performed by these same forces will have to supplement with these two extra discs.
But back to the set in question: No doubt about it, I like Perahia the best. Brendel is a little finicky and Marriner who accompanies him is a little too business like for me. Ashkenazy is beautiful, sensitive, and has a wonderful orchestra, but I sometimes question his cadenzas. I don't like Uchida, too Dresden china sounding, and don't like any versions played with fortepianos and original instruments.
Speaking of cadenzas, Perahia plays Mozart's, except as follows: He plays his own cadenzas in Concertos 1, 2, 4, 5, 20 (third movement), 21 (first movement), 24, 25, 26, and Rondos K. 382 and K. 386. He plays Beethoven's cadenza in 20 (first movement). He plays Artur Balsam's cadenza in 6. He plays Rudolf Serkin's cadenza in 21 (third movement). He plays Hummel's cadenzas in 22. Mozart did not write down cadenzas for all his piano concertos, so in some cases they have to be supplied by the pianist."