I've smoked them and they are really tasty, but it is easy to dry out the thin end of the fillet. I've found that a better way to get that smoky flavor is to grill them on a cedar plank. I soak a 1/4" thick cedar plank in water for at least an hour, then lay crappie fillets on it as tightly as I can, sprinkly some seasoning on (whatever I'm in the mood for, cajun is good) and put the plank on the grill. The grill is hotter than the smoker (probably around 500 degrees) and so the crappie cooks more quickly and is less prone to drying out... but the cedar plank will char and smolder around the edges and really add a great smoky flavor to the crappie. Give it a shot, my wife and I really like them that way and it's much quicker than running the smoker. I use the smoker for larger fish, mostly for steelhead trout.