they just give you more sounds, if you can set up with 3 crashes, 2 rides, a splash and a big 'ol china - then why not an extra pair of hats?
how about these (top / bottom) ;
12" AAX Splash / 12" AAX O-zone Splash
12" AA Splash / 12" AA Mini China
12" HHX Evoloution Splash (top and bottom)
or if you need a bigger sound, these...
16" AAX Bright Crash / 16" AAX Metal Crash
16" HHX Studio Crash / 16" HHX Power Crash
16" APX O-zone Crash (top and bottom)
i'm thinking about trying this combo for myself...
16" HH Duo Crash / 16" HH Medium Thin Crash
and i just pulled these outta Sabians book cause i know them, just remember - there are no rules!