Well no issue there, that's not giving PCs blindfolds. I can't stand as a player the secretive, hiding stuff that a player would at least be perceptive to. Things like someone wearing only a loin cloth, but attacks are not getting through, and you know you should have hit him. I'm not saying that as a player I should know he has an item that wears as AT 20, but I should know "something" is up.
Or your opponent has a 50 DB. Is that from parrying? Quickness? Shield? Other? Again, not necessarily knowing that 23 if from Qu, and 27 is from parrying, but a rough idea at least.
The GM type thats "Tell me your OB/DB and I'll roll for you so you can't know anything at all about your opponent, you just know you hit or miss" is very unfair to players