I upgraded to X because the latest reader 9 wasn't highlighting search / find terms consistently. Now with X, not only does it superficially look like a older version of reader, the toolbar customization is difficult, limited, and the search / find box is gone unless you hit the find button (or ctrl + F or apple + F). I use this feature all the time in writing scientific publications where I have to find a key word quickly when I'm reviewing articles and its very handy to just have the search bar on the toolbar. It just seems like this version has less features and versatility than the last. But the last has a bug, so I'm left with two less-than-optimal PDF viewers instead. Sure the some of the new features are going to be nice with X, but overall I think they took a step backwards with this new version, and should have fixed the bug from 9.4.5 first.