I started with the Roco multimaus and added the z21. I can use my tablet or smartphone with the z21 and the multimaus. I love programming with the z21, it`s a lot easier than the multimaus.
I use a electric paint stripper to heat the cardboard top be carefull not to over heat it. You could also use a hot clothe iron to heat the cardboard and pull it away.
Henk.