How can I put this simply...
The addition of FaceBook client logging onto the iPhone server is fair in every way. It was possibly designed to attract people to either pay more gralats for VIP, or to grow from just simply an iPhone/ipod application to a game on one of the world's hottest sites, FaceBook. The migration of players from the original servers of Graal on PC has nothing to do with it.
However, I do see these members from both points of view, since I had the opportunity to meet some of them, and fight others. Let me be clear; PC is not faster. On a keyboard, you can use one finger for every direction key. On an iDevice, you generally use one finger for all directions. It becomes easier to change direction, but is it really all about movement? You can't win a spar by simply moving. Sparring on iPod for two years and PC for two months, I can clearly see different fighting styles in both devices, both with their own advantages and disadvantages. Sparring is all a matter of how well you can read the other persons movement pattern, and how you plan to react to it.
Once this is said, it is clear that sparrers who have been playing graal for so long on the original PC servers may have an advantage at using their fighting style they've perfected for years. Yes, it becomes harder for people who haven't played the game as long. In all honesty, do you really think the devices play a larger role in this than a huge difference in experience? The device is your personal opinion and/or preference. Spar style can go a long way, either client you happen to spar on.