As a first time cruiser, I don't know that I would request a server. Just having someone's name that worked well for another family does not guarantee that they will be a good match for your family. If you request someone just because someone else reported that they did magic tricks or made napkin hats, chances are most of the servers do this so you would end up with someone like that anyway. Also it doesn't mean that server or serving team can't have an "off" cruise and you would have been better off with a different team. We have a server that we request because of allergies. He is a great server, for us. Last year, he wasn't his usual self because of the individuals in his station (he had a very large table that was very demanding of his time and kept him running back to the kitchen). He was apologetic to us but because we knew him very well we knew why his service to us was not "typical". If this was the first time serving us, we would have thought he was an average server.
What I would do, something first time cruisers rarely know to do, is to talk to your head server about what you need your serving team to improve to give you the dining experience you want. And if the fit isn't right, have the head server move you.