I haven't seen these issues. Can you elaborate?
When installing games, Origin frequently fails to complete the install. The latest case of this happening to me is DA:I, it took 4 attempts to install the game from Origin before the install would complete and actually let me play. 3 prior attempts would say the game was ready to play, but when I tried to play, the game went into install mode again and hung trying to complete the install. Did this to me for ME3 also at release, so it seems this issue is still hanging around.
The overlay can cause issues with game clients causing poor frame rates and/or crashes. This is another issue that has long haunted some users, going back to DA2.
As far as features go, just compare Origin to Steam. Some of the features that stand out to me are;
In Steam, take screen shots, record game video, friend list/messenger functionality is much more robust and reliable, Easier to set visible/away/offline visibility for friend list, can set games individually to auto update or not...
These are just some of the features off the top of my head that make me prefer Steam.