Hi Guys. I can comment on this. I bought an older MPP recently as well. Although my time to work with this device has been limited by my regular employment, I can tell you the following things about it based on my experience thus far:

1. I got the MPP Plus (think that's the only one available anymore) which has a battery and an audio out jack (though I haven't figured out what application would use the audio out at this point)
2. I charged it up and ran it today and the MPP ran 2 hours and 45 minutes before it died, with the screen intensity set to max. I really wasn't worried about the battery, since I can't imagine a situation where I won't have AC power for my keyboard, but just checked it to see how long it would last.
3. I will use it primarily for lead sheets. I don't expect to scan many charts in. I have built several fake sheets using Band in a Box. When I do this, I build the fake sheets using BIAB and then save them as JPEGs, BMPs or PNGs. With the latest version of BIAB, I can adjust the output file resolution to 768 X 1024 (which is the resolution of the MPP Plus). If you don't set the resolution to that size, it will default to a smaller page. Then when you import the sheets into the MPP, the MPP file processor will enlarge them, which can introduce some graininess. After I started saving my BIAB files to the 768 X 1024 resolution, they displayed much better on the MPP (no graininess at all). I can build a lead sheet using BIAB in about 2 minutes or so. Total time to complete a chart and export/save it is between 3-5 minutes. You can build a whole directory of sheets and then call up the MPP import tool and it will convert all the files quickly.

Bottom line is (so far) is that I like the MPP. It has a bright display, is fairly easy to use, and will be a lot better than thumbing through books, though they will be in my trunk in case I have a failure.

Two other observations. It is awkward to handle when it's not on a stand. After I nearly dropped it a couple times, I bought the MPP stand which makes it much simpler to manipulate. Secondly, the operating system is a little slow (takes a minute or two to boot up). But all in all, it appears to be a nice device.

Finally, if you go down through the Synth Zone listings (this forum) to February 1st, you will find another series of informative posts about the MPP.

Randy