Portapros vs high end headphones

Coming from PortaPros myself, I found that I looked for things that had more bass and treble since they sounded 'better' to me at the time. What you will notice with the higher end Sennheisers though, is that the musical presentation will be more accurate and clear, whereas the PortaPro is fairly clear, but has added treble and bass. It takes time to appreciate the difference, especially since most higher end headphones don't rely purely on bass to sound great. I think you will notice a difference between most any 2 headphones, but I'd just encourage you to buy and return as many as possible before keeping the one you like best... I had to go through 5 that way before I found something I thought was worth it in improvement.

I've been using my Portapros with Ipod exlusively lately and sure enjoy them a lot.  The HD595s don't have the bass volume of the Porta pros, I don't like the 595s more than the portapros, I hear a lot of hollow like cup resonance coming from them, they do have a bigger soundstage and more even tonal balance though.

I think a Grado might be worth checking out.  The HD650 also has good bass punch as well but is a little more recessed in the uppermids and the bass isn't quite as strong leaving a very strong midrange, depends on how you feel about uppermids I guess.  My HF2s have uppermids not unlike the portapros with a stronger treble too.  Best to hear for yourself ultimately.

If the headphones you're using are those from your avatar, remember: THEY ARE NOT PORTAPROS! You're listening to Sennheiser HD-800! And it's not strange that you love them so much.