the safety direction is reversed on the two models... the 602 is "backwards" by US standards, i.e.: Push it forward for safe and pull it back for fire. The 602's are a little rougher in the overall finish as well.

if that will bother you, then better plan on adding an aftermarket safety or look at the 550s. My big-bore BRNO was meant to be a "beater" backup to my double, so i was more interested in saving a few hundred bucks in getting an older 602. a good price on a used 602 would be around $500.00 - much more than that and you can get close to buying a new 550.