I had previously read the 1st editon of Icons, the french translation since we were lucky in France to have one.
This "1.5" Assembled Edition is a very refined version of the first Icons, the mechanics has changed a little because the GM is now also throwing dice for the opposition but this is still the same mechanic overall.
What you can do with qualities have been delimited and unified and you have now possibilities to create your character with points but, the random method is still the best if you want to keep the Icons flavour :).
There is now rules for experience, world building, villains building and Icons can now more easily be played in campaign, but I think that there are more adapted games for that ;).
Overall, I never regretted to buy this and this is a much more Iconic Icons than the first :).