All i know is 2 is a softer, smoother sound/attack than 5. So of the 3 commom types it would be ceramic, A5, then A2 in that order from the most punchy/clear/articulate to the softest spongiest attack and tone. I like them all in the right application/guitar, but none ios better than the other, just different. A lot of people seem to be under the assumption ceramic is bad, but that fact is it's best in some applications. I actually love it a lot of humbuckers, but single could i like with alnico and would choose 2 or 5 depending on whether i need more or less cut and punch.