Will superior earphones matter with my Nano

i have travelled a similar path. upgraded earphones make a huge difference, and i would strongly suggest you check out options among Westone's alternatives. The UM2 was one of my favorites. I tried just about everything that Shure had to offer, and didn't care for any of them.

All of that said, unless you are planning to (1) use an external amp (even a very small one) and (2) rip in a lossless format, i wouldn't invest heavily in fancy earphones as your upside will be very limited.

warren- Sorry you did not like the Etys. Mine are 6, not 6i although I will confess that I do not know the diff. Jeffreybowan2k makes a good point about limited improvement, but I found that the isolation the Etys provide was a big factor, esp on a plane or at the gym. I am not expecting hi-end sound. It does take some time to figure out how to insert the little suckers to get the seal you need for proper bass.

I tried that jammy over and over and I believe I had a good seal. No bass. I mailed them back to the Ebay seller and he said he won't take them back or refund my $$. We're doing the Paypal Resolution center route. Won't bore you with the details, but he says that I should go to the manufacturer for a refund. Give me a break..
I ordred my wireless WI-Gear headphones. Had them for a 30 day trial this past summer. I loved them. Absolutely great, but interference due to a US Coast Guard station on the path of my run, was a negative that took the wind out of my sail. Hey, I'll suffer the 1.5 miles. I do have another 4 miles of my run and perfection. Have other routes, as well...

Sorry you were not happy with them. Glad you have a good altaernative.

He made good on the refund, and I wound up with an apology. Fancy that. He listened to the earphones and found that they were truly lacking in bass and were probably not defective, but just plain ole poor in the bass. whattayaknow. He is refunding my $$. I thought that was a lost cause.