midi controllers vs digital pianos

Hi everyone!
I´m from Bolivia, I´m new here and I´m full of questions.
I´m playing an M Audio pro 88 full weighted keyboard controller, but I have few control over it, since the dynamics don´t work right in it. I need another instrument, but I don´t know whether to get a digi piano or another controller. The midi software I play has a great sound (The Grand 2 of Steinberg). Better than most digital pianos, but I´m afraid to get another controller and have same problems.
THANKS!!

If you want a weighted action that will give you the feel of playing an acoustic piano, you are probably better off buying a digital piano that has master controller capabilities. A good quality weighted action midi controller starts to get into the lower price range of some good digital pianos. If a weighted action doesn't matter to you, then look at some other controllers.