Are you talking about holes designed into effects cymbals or are you talking about large numbers of rivet holes?

I guess "effects" cymbals, but there seem to be whole series of crashes anyway (i.e. Sabian Ozone, Istanbul Xist, etc...) Just not clear on their purpose. Purely visual, I guess, hence the question...

It definitely affects the tone, it adds a bit of trash, like the flange on a china.

Yes, the larger "O-Zone" type holes definitely "dirty" up the sound and add some bite and trash. They usually make the cymbal quicker to react and quicker to decay (not as much metal). Also, and this seems counterintuitive, but it also makes the cymbal louder. I was talking to Greg Zeller from Sabian about it, and he explained it to me but I can't really remember why. I do remember him saying that their 21" AA Holy China is the loudest cymbal they make.

So it is not just cosmetic at all, it definitely affects the sound. My favorite of these newer effects cymbals is the Wuhan Linear Smash. They make a 16" and 18". They are normal cymbals (not chinas) that are very thin and have a slight downward flange at the edge from where the holes stop. Sounds exactly like it's supposed to! Best of all, it's inexpensive! Why pay for a K. Zildjian or A. Custom EFX crash when it's going to sound dirty and trashy anyway?

To me, these effect cymbals sound a whole lot better if they are thin. Otherwise, they sound clanky and unpleasing (Like the B8 and XS 20 Sabian Ozone Models). I have used this cymbal on lighter rock and greasy funk type gigs, and it sounds great. Certainly not your typical crash sound, but very pleasing and blends in with the music. Very Stanton Moore-ish. His trash crashes sound terrible by themselves, but within the context of the band they sound great!

They also don`t have overtones that last forever. If you have a cymbal that will ring till tomorrow, putting holes in it will drop that time to seconds.

Interesting. What about durability? They are no more likely to crack? Just curious. Also, are they all made the same way? I think I read that Zildjian cuts the holes with a laser; I sort of doubt Istanbul has a laser, but maybe I'm wrong?

I would think the last thing to cut the metal with is heat. You don`t want to temper the metal. Water jets can cut just as fast and clean but no heat at all.

I really don`t know when they make the cuts or punches during the manufacturing, but you will find lasers in Istanbul. You just cant access the NATO base.

From Zildjian's website:

[COLOR="Blue"] 14" A Custom EFX

Drumset Cymbals / Cast Bronze Cymbals / A Custom Series / Special-Effects

This special effects Crash cymbal has a unique set of laser generated "cut outs" that allow it to produce a quick, dry and trashy sound used for accenting and punctuating. The brilliant finish makes this "must have" shimmer like any A Custom. The new smaller size is a great addition to your kit.[/COLOR]

I agree heat a laser seems like a weird way to do it... I'd have guessed a punch or something. No idea how others do it.