I don't think the 4th gen iPod is much thicker than the mini. The 4th gen is slightly thicker than my 5th gen, but my sister has a mini which is also slightly thicker, so I think the mini and the 4th gen are about the same.
As for the mini-drive, it's really no concern since you don't give it much abuse. My 30GB iPod still works fine, and I shuffle around songs alot, as well as physically abuse the thing.
And yes, the nano is frail, but keeping it in your pocket won't break it.
My iPod mini died last week and even though it was only 11 months old, since I can't locate my receipt, the creeps at HP won't service it.
That said I'm looking at replacements and wanted your collective advice. I'm a 50 year old Sales Engineer and I use my iPod constantly. When I'm traveling from refinery to refinery, it's plugged into my car and when I go to sleep, it's in my front pocket. I mention this because I don't use it in lots of places where it can be dropped or damaged...like jogging, walking around etc.
I have about 35 GB of music on my hard drive as well as audio books. So the units I've considered are:
IPod Nano 4GB at about $170.00
IPod Mini 6GB at about $150.00
IPod 4th Gen 20 GB at $100.00
All are refurbished. The Nano appeals because I worry about the mini-drive dying. Should that concern me since I don't shuffle around song lists a lot. But I worry that the Nano is a tad frail.
The 20 GB appeals but is it really bulky compared to the mini I've been using?
TIA - and apologies for such a long post but my iPod was about the only thing I own that I really care that much about.