I have noticed some erratic behavior on compile.
I've first seen it immediately after installation when trying to recompile the IDE, which failed. I've tried again after removing and adding back some packages and observed that compilation fails at different places with different errors. Sometimes it was enough just to try compiling again and it would compile fine; sometimes I'd need to restart Lazarus and then it would compile fine. I'm not 100% sure, but I think it mostly failed when I clicked "Save and build IDE" in the package install/uninstall dialog and "Build IDE" menu item, while chosing "Configure Build IDE" then clicking Build mostly did fine.
Errors I got were compiler runtime errors 1, 2 and 226 with no details, or a strange message about being "unable to compile resources". The runtime errors also sporadically showed when compiling a project afterwards. There is no rule how and when those errors happen, they have appeared erratically, and another try usually goes fine.
On the same machine I previously had Lazarus 1.4.4 (and earlier versions before) and never encountered anything like that, nor have I with 1.6.0 on another machine...
And another issue, when I install educationlaz package, I lose the Palette! It gets replaced by an empty panel.