Yes, of course there wouldn't be any music management software on the 5100, and I have no doubt that the mk3 would've been the better product (I've owned a Neo35 so I know about how well it 'manages' the mp3's - NOT!). It's just that are first glance the pure hardware specs looked really similar. (and by this I don't mean of course that every transistor is the same)

Riocar 58gig (48gig + 10gig IBM travelstar) S/N : 10101747 red