Apple might streamline their offerings, simplify them dramatically, but they also aggressively update it. Where the Nomad came out and was incrementally improved the iPod got re-invented several times, often cannibalizing its own market share in the process.

Part fashion accessory, part music appliance, part computer, the purpose of the iPod was understood by Apple and poorly understood by their competitors.

Just like how the Walkman wasn't the first portable cassette player, or even technically the best, Sony relentlessly innovated on that form factor making smaller, lighter versions, waterproof ones, and ultimately owned that market. It wasn't until the iPod rolled around that someone displaced that position so completely.

you are correct. I was on my second HDD-Based mp3 player before the Ipod came around. I Also had the Nomad and replaced it with the Zen. Googling I see dozens of models, but I believe it was the Zen Xtra. I still have it in a box of old electronics.

I recall it being very difficult to explain to my peers what I was carrying. Thankfully the nomad looked like a CD player.