It's impossible to judge whether a player is any good or not by basing your decision on his performances in the SPL. The SPL is an easy escape for the world's have-been players as they will shine in comparison to the mighty Dundee Utd or Motherwell.
You only have to look at players like Jean Alain Boumsong who excelled at Rangers and then struggled when he joined Newcastle, who play in a proper football league. Then you have players like John Hartson, Rod Wallace and Stan Varga who, after struggling in England, become superstars in Scotland. Can you believe that people were suggesting Chris Sutton should be recalled to England after scoring a few goals for Celtic?!?
As to the more precise question posed by the OP - I'm not terribly familiar with Kyrgiakos. I'm sure he'll do a decent job at a mediocre team like Eintracht and relatively weak competition like the Bundesliga but I would guess he would struggle playing at a high level of football.
I need to get laid