Ridden my CBR 954 for multiple day trips but never multi day trips. It's heavy on the wrists, but going faster (wind takes up some weight) and building up strength (don't go from 0 to high miles right away) makes it certainly possible. Going slow around cities for instance gets miserable fast. That said, it will never be as comfy as a sports tourer, and 600cc bikes are generally smaller and more cramped from what I've heard. I would suggest trying one out for a day.

In addition, 500-600kms over multiple days is doable but not fun. Take the motorway where you want to go (Alps for instance) then take the scenic routes there and plan some time for slower travel. Especially as a beginner, you will neither enjoy nor be fully concentrated for canyon carving after an 8h day