This is a bit of a strange animal — physically, it feels a bit fragile: the housing is plastic, and the unit is relatively thin and light. However, the actual pads and buttons are very responsive and feel *great* to the touch. So long as it can stay stationary on a flat surface it feels very good. I'd be wary of traveling with it though.
In terms of function, the Launchpad is incredibly capable, especially when using Ableton. Some of that functionality is difficult to reach, however. The basic operations are easy enough to access — the buttons, knobs, and grid arrangement are all clear organized and labeled. However, the lack of screen does make some of the more complex functions (e.g., scale mode) annoying or even daunting to use, as there is very little feedback on what setting is active. (This despite some clever workarounds using the colored pads to show settings.) The key combos for many hidden functions can be easy to forget, also; which has required me to keep the manual within easy reach. this kind of hampers the "spontaneous creation" this sort of controller is meant to inspire.
So overall a good product, but could be immeasurably improved with a small screen.