I have actually been using osrose servers since rev 16.
There were a few bugs but nothing really major
It was more a case of some things just not working than stuff that was doing really bad things like dying when you walk and such.
I never really had any problems with it.
Then again i was never part of the dev team so all my modifications stayed in my own server.
I just prefer the pre-evo version of the game. Always did.
It is only very recently that we actually stared work on osprose and that probably explains why the project is moving forward so fast right now.
To be quite fair though, we started out with a base code taken from osirose so most of our server is identical to Arnold's.
All the devs on all three servers share our code improvements so all three are making a lot of headway. It is only the release methods that are different.
osirose and osprose make every change public on the svn as they happen.
osrose has a private svn for development and releases stable versions to the public after extensive testing. Rev 80 is very stable. Rev 81 is almost a completely new server. It is designed for a completely different client (post 139 NA) and will not even be compatible with the older clients currently used on rev 80. that is why the next rev is taking so long.
osprose will always be pre-evo. That was why we started it, so that we could use the pre-evo system which many of us prefer over the other systems.