I've been a dedicated PX-100 (original version) user for the last 5 years, but the left side started cutting in and out last week. The price has gone up to around $80 now, I guess because Sennheiser stopped making them (big mistake!), having replaced them with the PX-100 II. So I decided to try the Portapro, which sells for $30.
My first impression is that they don't sound entirely different from the PX-100, which is great. After a few hours, I can say that the main differences between the two are:
- Portapro has better treble detail
- PX-100 has a richer, fuller midrange (especially noticeable with vocals)
- PX-100 has slightly tighter bass
I still think I like the PX-100 better, but for less than half the price, I'm thinking Portapro will be my new portable phones of choice.