Time out - headphones?

I made an impulse buy today and picked up a pair of Sennheiser PX100 headphones. I still have my trusty Koss PortaPros and both of them sound AMAZING. If you're still using the cheapo earbuds that came with your iPod or cd player, get one of these two babies and you'll never want to listen to your favorite tunes with anything else! Alright that's the end of my marketing spiel. Guess the Portas are a little more bassy and warmer, but they are both good in their own ways. The Senns might be a little bit clearer, but that's probably me trying to pick out every nuance just to find some difference. No regrets so far!