I'm sure you can easily fix it. Sounds like it's got some dirt on it. Take it to some repair service that can handle keyboards, maybe just some cleaning will do it.
The new Impulse seems good to me. It's got the same keyboard and two wheels instead of the joystick. Doesn't have the useless X/Y pad on it, and the knobs and faders seem better. They say the pads are useful now (for more then triggering clips on live or on/off dutties lol). Don't really know about others.
