I have recently used a spongy-feeling overgrip by victor, i don't think it is the basic grip, as it has victor logos printed on it, and too "spongy" to be the basic grip. neither should it be this GR-218 grip (based on the observation that the logos have different distance). So, I ordered the GR-218 in hope to find out exactly what it is. If you are the guy that i traded ns8000 with, will appreciate if you inform me what grip it is. (as i can't remember your BC name)
this is how i feel about each grip, in comparison to GR-218: yonex super grap: gives burning sensation to my hand, if wrapped tightly, layer becomes thin and rigid. yonex Arc grip: gives cold sensation, leatherish. GR-218: thickness 0.5mm, but feels thicker than supergrap, very spongy indeed, does not burn my hand like supergrap, durability is probably better than supergrap, a very interesting and comfortable grip...