Well, YJ---
the Sportas (which I have) have overemphasized bass which washes out the mids too easily and trims articulation (the ability to separate one instrument from another as both play simultaneously). These are warm phones, which have good low bass extension, though it is not precise or balanced. Soundstage is adequate though suffering a bit from the heavy bass. They don't sound terrible with classical but are obviously made for modern bass-heavy music. The Porta (which I heard) sounds almost exactly similar. The Sportas also leak a lot of sound to the outside world to delight/annoy those around you.
The 35s (which I have not heard) have the same drivers as the Sportas/Portas but position them a bit farther from the ear. The overpowered bass is cut down quite a bit and the overall sound is more balanced and elegant (according to reviewers here and elsewhere.)
The SR60s are somewhat bright, i.e. emphasis on treble, but not terribly so. Bass is very tight and not too prominent. Indeed bass can sound almost non-existent with the 60s if you are accustomed to hearing gobs of sloppy bass from other listening. Mids are well balanced, and the soundstage is a bit broader than the Sportas. Articulation is great. The Grados have a unique "up close" presentation that in my experience is rare in headphones---you feel very close to the musical source. They are in my opinion, much superior to the Sporta/Portas as a means of reproducing music. They also have massive sound leakage, much worse than the Sportas.
Many Grado haters feel that the 60s have muted treble. I feel this is noticeable only in comparison to Grados at the 125 level and above, and certainly not in comparison to other phones of similar price, e.g. the Sportas.
If you wanted a great set of home phones, the SR60s would be ideal (and they look so cheap that they would probably pass under the wife radar! ) but for portable use, especially when working out, I would go for the 35s. The Sportas are too imbalanced, though I like mine, mainly because I have other options if they get too tiring...