The TRS-80 Model 4P was the next generation of the luggable computer. The Model 4P is better constructed than the Osborne 1 with a stronger outer case and all metal internal chassis. The screen is larger in the Model 4P, but the floppy drives are smaller. Check out the TRS-80 Cracking Open Gallery for all the details.
After cracking open both machines, the Osborne 1 comes away as being the prototype for the second generation Model 4P. We talked before about the Osborne Effect where, so the story goes, Adam Osborne shot his company in the foot by talking up the next generation portable computer his company was producing before it was actually on the market, which effectively dried up the market in anticipation. Well, I think the refinements of the TRS-80 Model 4P and the competitive advantage it obviously had over the Osborne 1 may have actually been responsible for the Osborne Computer Corporation's ultimate downfall.
I know some of you were around and paying attention in the early 1980s, what do you think?