Pros: Sound quality, comfort, design, aesthetics, design hasn't changed since '84, uses KSC35 drivers, just in blue instead of black.
Cons: May be considered to be dorky and ugly by the Beats, Soul, Skullcandy, and Bose crowd.
I got a pair of Portapros last month, along with a Sansa Clip+ 4GB, these headphones sound really, really good for $40, especially with an EQ'd Clip+, and I had UR40s, which are also great bang-for-the-buck headphones, sound great, comfortable as can be, however they're not as portable as the Portapros are. Unfortunately, the UR40s died due to a short in the plug a few years ago, so I lived on MDR-V150s and Bass Freqs, both of which are OK for the price, but not as good as the Portapros or UR40s.
On the comfort aspect, the Portas are extremely comfortable, especially on the "Light" setting, and actually a bit more comfortable than my old UR40s and way more comfortable than my V150s or Bass Freqs, V150s get painful after a while, and Bass Freqs just feel weird after a while. As far as aesthetics, I dig the vintage styling vs. a pair of Beats Solos, but others may prefer the styling of the Beats Solos.
To go into more detail on sound, the Portas have plenty of bass while still allowing plenty of mids and highs, and overall sound really sweet, beating both the Bass Freqs and the V150s, and rivaling the UR40s.
Overall these are a great bang for the buck and are quickly becoming my primary headphones, while the V150s and Bassfreqs are going by the wayside. And this is my first review on here so it may not be very good.
PS: may get some KSC35s at some point and stick them in the UR40 housing to see how the Portapro drivers combined with an open-back circumaural enclosure sounds vs. the open-back supra-aural enclosure of the Portapros/Sportapros. And considering the Parts-Express headband mod for KSC75s as well. In addition, the Sportapros are just a cheaper, more modern-looking version of the Portapros that don't have adjustable temporal pads like the Portapros, but can be converted to behind-the-neck, as they use the same drivers as the Portapros.
Best uses: All-purpose, great-sounding set of open-back on-ear headphones in the sub-$50 pricerange, sound great on MP3 players, computers, or home stereos (although an extension cord may come in handy for use with a stereo). Sound great with pretty much every genre.
Ideal audience: people who would rather have a vintage-looking pair of headphones that sound great and only cost $40 than a pair of Beats, Souls, Skullcandies, or Bose headphones. Basically people who value sound quality over looks.