I just love my Zoom.
I've heard better quality recordings from people on the forum, but they've always involved more expensive equipment (sometimes MUCH more expensive) and elaborate setups and fiddling about with mic placement and levels. The Zoom hits a balance between ease of use and quality of recording that is exactly what I want.
Rodney, I don't know if you've ever braved reading the 17-page long Zoom Mega-thread, but if you do, you'll find lots of discussion about mic placement and how to adjust the input levels to improve the quality. But I will have to say that I thought your recording quality was pretty darned good... I'm not sure you'd get appreciably better with the Zoom. (I agree with SideShow that one of the limitations of the Zoom is that the recordings will have a bit of a muffled tone.) Link to Zoom Mega Thread
You should also try playing the .wav version over a high quality stereo. The sound is much better than what you'll get with an mp3 conversion.
p.s. My compliments to your son. I love Meat Loaf, and my playing at my best doesn't come close to his "noodling."