I suppose to an extent PASOE vs Classic is a question of what you're doing. But ultimately, when 11.7 is retired, the Classic AppServer will go with it. So in essence it's irrelevant if PASOE is better or not: PASOE is the
only route forward if you want to stay up to date with OpenEdge (which you should).
That being said, PASOE is a big step forwards in a lot of areas. To name a few:
- Security - it's a Tomcat server and therefore uses Spring Security
- Online maintenance
- Performance as agents persist, so less overheads for setting up and tearing down
As Tom says, in general the migration is very easy. The only real challenges come if you're using WebSpeed where it can be a little trickier. But that being said, you'll have to do the upgrade one day, and the benefits of OE12 and staying current outweigh that pain.