In questo post Eric Gunnerson parla del'implentazione "Type Erasure" dei generics in Java.
http://blogs.msdn.com/ericgu/archive/2004/09/23/233438.aspx
Importante notare che Gunnerson dice in termini più approfonditi più o meno la stessa cosa che io avevo rilevato qui e qui
"This means that Java generics doesn't give you the performance benefit that .NET generics do - not only do you not have the ability to create generics on value types (not that surprising given that Java has previously not had boxing), but you still have typecasts in your"