Yes Diki, that is why I said "...if just loading pdf's.." Note that I did go on to say we all do get tempted to load other things. A LOT more

And if you can actually tell the difference between a 256 mp3, and a 320 mp3 you are better than 90% of the population

And I reckon the other 10% only THINK they can hear a difference

If I did a blind test you would NOT pick the difference!! For backing tracks why on earth would you want to use a wav file for goodness sake!!!! Way too big for no discernible benefit.
And as for midis, sheesh you could fit a gazzillion into 16 gig!
My iTunes collection is at 9 days worth of continuous music(about 14GIG) and I have ALL of that on my iPad, together with all the MP3 backing tracks I use, all the midi files I need, my PDF book collection (as in novels etc) all my PDF manuals, all my PDF charts and scans, two dozen apps with associated data files......
AND Angy Angry Birds!!
I still have nearly 35% storage left. Mine is a 32gig model.
If I was buying now, after careful consideration of exactly what I use my iPad for, I would definitely go for one of the deals for an iPad 1 64gig...Much better value. I would also make sure I got 3g as well.
Dennis