Pros:Durable; foldable, smart construction. Lifetime warranty. Good resolution.
Cons:Somewhat too high impedance? Really none.
The Bottom Line: Good portable headphones, durable, accurate-sounding. A "must" replacement for any bundled headphones.
First of all, it's a bit of surprise that those were called "geeky" and "dorky", probably suggesting they look "cumbersome" or somesuch (the very notion of something being "geeky" or "dorky" is laughable by itself - quite a prejudice for discrimination).
Recommend this product?
The Porta-Pro look like a toy. They're small, tiny even. Collapsed, they fit in a hand's palm. The design is original - those are recognisable headphones.
Those are open, dynamic headphones with a somewhat unusual impedance - 60 ohm. They're quite sensitive though, so in reality this means they'll need a bit more current than 16-ohm or 32-ohm headphones or earbuds (in fact, they're almost as efficient as earbuds). Even with an underpowered portable player running off a single AA battery, the Porta-Pro can be driven loud.
Unlike Sennheiser PX, the Porta-Pro fold within the headband (PX enclosures swivel 90 degrees to fold; Porta-Pro enclosures fold without swivelling), into a ball of sorts, with the metallic headband protecting enclosures. This is very effective: the "cups" themselves are protected from any mechanical damage by the headband and rims acting as bumpers.
What's really special about Porta-Pro is the lifetime warranty, which indicates Koss taking their durability seriously. They may look somewhat flimsy-built, but those are only looks - there're people who've had the Porta-Pro for more than a decade.
The headphones are really more comfortable than the somewhat "industrial" looks suggest; two pairs of support flaps on the headband offload pressure on the skull, relieving ears from too much pressure.
Sound reproduction is warm and musical; the Porta-Pro are warmer and perhaps less of a "sound blaster" than the Sennheiser PX100, but they also lack some of the detail of the PX100. With that, the sounding can be more natural, especially because of the more relaxed, laid-back presentation.
The first impression those headphones will make is "how can those have such a large sounding?" Another reviewer called them boombox-like, but in reality they just emphasise bass according to an HRTF model. They're not as natural-sounding as, say, the K-240 Studio, but for less than half the price, the Porta-Pro are maybe the closest (except perhaps AKG's own K-24P).
They're not as revealing as some of the pricier choices for portable headphones (Denon AH-D1000, AH-C700), but resolution is good; enough to portray what there is, even subtle synthesised pads. Porta-Pro won't all of a sudden bring out (previously unnoticed) hi-hats or high-pitched instruments playing in the background (like Denon headphones might), but they won't blur them into non-existence either.
All-in-all, a worthy and durable replacement for any portable player bundled headphones.
Mini-mod Update: foam pads can be removed and replaced with mini-cushions. The cushions have to be deep enough yet small enough to fit on the plastic diaphragm holders. "Doughnut" cushions from old Technics supra-aural headphones were glued on; they're a tad too large though, cushions for AKG K-26P/JBL 410 might fit naturally.
This replacement removes some of the constraint in midrange/treble, and makes the overal sounding more natural and airy. The tradeoff was some bass: bass transmission depends entirely on seal created by cushions, and so better-designed cushions like those of the K-26P would preserve all of the frequency response without leaking.