I do have the Aiaiai tracks, as well as previously having Grado SR80. I also own the Bowers & Wilkins p5, the Sony XB700, and the koss portapro, koss ksc75, sennheiser hd215 and have tried the AKG 420s (which are pretty genuine at JB HIFI). Tracks are.. unique and I love them when moving about. They do very well on the road and sometimes amazes me with their ability. Eg: While at the zoo walking about, playing Aerosmith's Jaded, I was tricked several times and was convinced that the occasional cymbal notes came from beyond the zoo walls... Also, at Bunnings warehouse, playing most live band music the headphones made it seem as if the concert was beyond Bunning's next shelf. I kept peaking around corners just to confirm that its my headphones, and that Dave Matthews isnt actually playing at the warehouse... In comparison, no other headphone of mine were able to do this, not the Grados, not the P5. The grados however are better sounding, and the P5 i love, for their build and more neutral sounds.
I've tried the 430's and 450's at JB-HIFI, and honestly I thought the 420's sounded better, and were ALOT more comfortable and fit better, on me.. but thats just IMHO.
V-jays are decent, but the aiaiai tracks are better. HOWEVER! do try the C-jays.. they're pretty much the top ultra portable dog...
KSC75 are excellent, for their price of 15 dollars.. i got TWO for 25!!! lol but as SQ goes, do not expect them to blow your mind away. They will not be able to match the Tracks, the CALs or the Jays... or the AKG's