i hate my ice perc... i PREFER warm water or actually hot water... it gives a steam effect and i find that ice chilled air tends to be very HARSH.
the only time i'll use ice is if i have my vape attached to the perc which is a rare occasion...
another thing i'll do instead of ice is i'll allow the bottom of the glass to sit in a sink of ice (water is cold but no ice IN the bong)...
for me... ice is negative. but with a double perc, 2 diffusors, and a water ash catcher i dont feel the need for any ice in that thing. besides if you put ice in it and you have hard water... WATER SPOTS... makes your glass look shitty.