the whole reason it has some problems loading "known formats" as you call them poorly, is because the Office formats are *not* 'known'. MS stopped releasing the office file format specs after office 6.0 IIRC -- everything since is just reverse engineering.
Which is complicated by the fact that it's mostly a binary memory dump out of office itself. Even the office 2007 OOXML format blows -- while it is supposedly described, the official spec is riddled with bits that literally say "do this the same way word 95 does it", without going into any details about how that might be. And since those are closed specs as well, that still means that you end up guessing what to do with it.
This is one of the reasons that the EU's anti-trust case against MS has mandated them to release API's and fileformat info, because there can never be a level playing field as long as MS has a monopoly and hides the interoperability specs from the rest of the world.
Note that this info *was* out in the open in the past, when WordPerfect was the big dog -- but once MS became #1 the publically available fileformat info magically didn't get updated anymore while the document formats themselves kept evolving.
Which is complicated by the fact that it's mostly a binary memory dump out of office itself. Even the office 2007 OOXML format blows -- while it is supposedly described, the official spec is riddled with bits that literally say "do this the same way word 95 does it", without going into any details about how that might be. And since those are closed specs as well, that still means that you end up guessing what to do with it.
This is one of the reasons that the EU's anti-trust case against MS has mandated them to release API's and fileformat info, because there can never be a level playing field as long as MS has a monopoly and hides the interoperability specs from the rest of the world.
Note that this info *was* out in the open in the past, when WordPerfect was the big dog -- but once MS became #1 the publically available fileformat info magically didn't get updated anymore while the document formats themselves kept evolving.