You can't exactly base screen size on pixels -- for instance both the TheaterTouch and UCommand 616 have the same screen resolution, but the UC616 has a larger screen.

The best way to calculate is with square inches. The Pronto's screen provides 7.13 square inches of space. The MX-1000 provides 4.83 square inches, which is about 32% less. However, you must also take into account the increase in hard buttons -- which means you need to use the screen for less -- and the fact that the MX-1000 has a large user editable region.

Hardware-wise, the MX-1000 is great. I'm hoping the software will soon grow to match.