sharp fret ends, yep, you get them.. when i shopped for my faded over 10 years ago, i had to rifle through to find one, the one i bought, that didnt have them..it that one store..other stores later on, i found all of them were good...theres bad apples in every bunch it seems..
don't forget about the Iommi's, i swapped out my 490 in the bridge for 1, and 500 k push pull pot.. and even with the 57+ in the neck, its about as loud as the neck...+1 on leveling the pups too, that helped my sound...
i think with humbuckers it does..it levels both to be even with the strings..i noticed a difference when i did it.. like i said, with p-90's, i didnt do it, i can't see it making a difference, being single coil..i may be wrong.
i did that on my humbuckered Faded, didnt with my Classic.. i tend to believe sound wise its not necessary due to them being single coils. unless its for the looks.. i did hear an improvement after doing it to my Faded for sure