The 3rd gen Nano is a great form factor - put the 3rd and 4th gen side by side (as I saw in an electronics store last week), and the 4th gen looks fugly and really big and tall. The 3rd gen looks small and pocketable. THEN actually try to use the 4th gen and marvel at the ridiculous "feature" of having to hold it sideways to watch video

Apple really messed up with this redesign.
(The first and 2nd gen nanos also look weird compared to the 3rd gen - they were fine at the time, but in hindsight they look too big).
Of course, the above is just my opinion (I think I'm right though!)