>I generally find sys(2011) more useful...

I don't find a use for it at all, its easier to write ?IsExclusive() than ?sys(2011) = "EXCLUSIVE".

Besides, it does have some issues, like, it will only tell you if a record is locked in the current app, not anywhere else, so to make sure you're truly safe to save, you should have:

ISEXCLUSIVE() OR ISFLOCKED() OR ISRLOCKED()