Comparing Danielson and Kasper's Griffins stints is a tough one for me. Kasper didn't really get an offseason going into that year and obviously started slow. But he also had the advantage of playing against men already in Sweden plus the Griffins team around him was much better. I think he played with Berggren mostly who is a very good AHL player. Danielson was on a much worse team and was basically asked to be their best player (top line center, pk and pp). Having Watson as your main winger is a tough ask and they didn't really have a defender good at breaking the puck out, they really missed Johansson and Edvinsson back there.
So it is tough for me to say who was "better" but I think they both had pretty solid seasons respectively.