If you don't know, the Orion client shows orbs alongside the minimap that display a player's current hitpoints, prayer points, run energy, and percentage of special attack. It also shows players their hits, in a fashion similar to that of the Xp pop-up that the live game currently has, only it predicts the actual hits, not the Xp given as a result of hitting that number.
Obviously, this is an advantage to players who use the client, especially in PvP - noting the client can do other things like look up prices on the OSRS Price Guide.
I have been using this client for a few weeks now, it seemed to be perfectly legal to me - although I'm not a programmer so realistically I could've been way off and the advantages were too good to pass up. One of the emerging theories is that if this were illegal because it gives some players an 'unfair advantage' wouldn't a tool like DGSweeper be illegal, because it also gives players an advantage. Just like the DGSweeper, this client does nothing for you except display statistics, it cannot make your character do anything, and that's what separates it from a botting client.
What is your opinion on the client?
Is this advantage unfair even though anybody can use it?
If it was unconfirmed, would you think it's legal or not?