In terms of non-2 stage jacos vs parmas. the offsets of the jaco tires are different than the parmas. The jaco's will make your car about 2mm narrower, which is neither good nor bad, just different. You can widen out the car with widening shims, but that will give the car positive scrub radius, again not good or bad, just different. Also, althought the shore ratings are similar the grp rubber is a little different and the width of the hard "orange" outer shoulder is wider slightly on the jacos. Again just different, not an advantage or disadvantage. Obviously the 2-stage tires are not really comprable as they are a very different in construction.
Speed Merchant/Corally USA/Specialized RC/Team Kwik/Tekin/Sweep/Parma PSE/Team Pickles Performance