0603 size has a somewhat higher inductance, so it may not perform as well as 0402. Whether that's significant, I don't know.
Soldering 0402 has one advantage though: after you pick and place 10000 of them, suddenly 0603 seem as huge as bricks.
indeed - i can now do 1206 with my feet!
thnx, will read up a bit on package characteristics.