I have used several CMS systems over the years and, each time, became frustrated with dealing with upgrades and add-ons.
ocPortal is different in that many and, most importantly, most of the features requiring add-ons are built into ocPortal. Those that aren't are frequently delivered by add-ons maintained by the ocPortal developers. The result is that updating to the current release is much less of a crap shoot and instead just works subject to any mods you have made.
The software is very stable to begin with and benefits from developers whose attitude is that bugs should not be put on lists, they should be fixed.
Yes, there are areas that can and should improve, but at this point, I consider ocPortal the best solution for a "canned" CMS. For a current project, I decided to take a look around once again at what was available and chose ocPortal - and I am happy that I did.