After 3 months of use of the new (for 2010) Version 6 (V6) Nano, I think I have enough experience to give you my two cents.
-My favorite new feature of the Nano is the Radio Live Pause feature. I'm sure that most runners that would like an option to their iPod that allows them to pause while listening to a radio station. More important than the V5 (Version 5), you can pause what you are listening to for up to 15 minutes if you meet someone at the health club or out on your run. The radio on the V6 Nano allows just that. Like the V5, when you are running in a health club, the radio channels listed under the TV screens are available on your iPod.
I was so impressed with this feature I figured that my new iPod iTouch would have this. But in case you are wondering, it doesn't… go figure.
-Weight – an item that allows high on the list for runners is the weight of what they are carrying, especially for long runs/distances. Yes, this is lighter than version 5. But seriously, any of the Nanos that have come out in the past 6 years have met this requirement. Okay, it's lighter, but I can't believe anyone would notice the difference from any of its former predecessors.
-Touchscreen. If you are an owner of an iPod iTouch or iPhone, you will understand the advantage of the Touchscreen vs. the scroll wheel. But this can also be a disadvantage (see below). Because it is so small, there is so getting used to it, especially those folk with large thumbs, but I found it easy to assimilate to.
-Clip – don't know why they waited so long to add this feature but it was a good add. Instead of needing to buy an accessory to hold you Nano when you run, you now have that built in to your device. I find that I use this all the time, but it wasn't as if I had to have it. As a marathoner, I own shorts with multiple pockets for gels, etc. and the smallest pocket can easily fit the new Nano. I have to believe is that the accessory dealers aren't crazy about adding the clip, but for the rest of us it a good add.
-Heart Rate Monitor – in case you didn't know this, you can buy a Polar Heart Rate monitor that works with your Nano V5 or V6. This one syncs easily and it shows the beats on the bottom of the screen which I find cool.
-My first one is a big one, no external speaker. One thing that I loved about the V5 Nano is the external speaker. I don't know if everyone ran into this problem with past Nanos but I would religiously pick up the Nano and find that I had no battery life left. That's because I forget to turn it off! When the V5 came along, as soon as I pulled out the ear buds from it, I could music playing and it would tell me that it was still running. That alone made the V5 worth the price, no more not-so-smart battery draining. It also was nice to know you could listen to music if you didn't bring along your ear buds. For the life of me, don't know why they got rid of that.
-Removal of Video. I know I should be upset that I'm losing this feature while having to pay the same price, but I'm not. I didn't watch many movies or MTV videos with my Nano in the past, and the screen is so small why would anyone? I can count the number of times on one hand that I took videos with the Nano. To me, it was a nice feature but far from a necessary feature. But I can understand if someone only had the Nano as their lone iPod device.
-Glitchy with Nike Plus system. I am currently on my second V6 Nano. The first one I had has the same problem that my second one has. When I run an extended period of time, say over 1 hour, it starts to skip, and say "Workout Paused", then skips to next song, "Workout Resumed", skip again, "Workout Paused" very annoying to say the least. I can't figure out if it's using the remote stereo Apple ear buds, the Nike Plus app or what, but it takes away from using the Nike Plus to have this happening. Because I am on my second V6 Nano, I know it wasn't just one bad unit; it must be something in the iOS.
So my overall rating of the new Nano? I'd give it 3 out of 5 stars. (My rating on the V5 was 4 out of 5). If you've never had a Nano, I'd say get it. Or course I would recommend a V5 Nano if you can pick one up, but if not, the V6 has enough of the bells and whistles to make it worth the money. If you are looking to upgrade, I'd say wait. I think there are some bug fixes that they need to deal with. Also, as I stated above, I really miss the external speakers on the last Nano. That alone was reason to just keep a version 5 instead of going to version 6. I actually wish I wouldn't have sold mine to a friend so quickly. But I couldn't have justified keeping two Nanos. Overall, I say wait until the next version to have them fix the bugs and get the external speaker added to the next version.