Glass newb here... I'm interested in using ice with some glass I'll be getting soon. First question, does ice make much of a difference? I've actually never used any.
It will cool the hit.
I personally like an ice-cooled hit, but I never have any ice handy.
It's not something I'd go out of my way to make sure I've always got ice handy, but if I've already got some ready, I'll probably use it.
Whether it makes enough of a difference to be worth doing is a preference thing. (and there are some members here who prefer using warm water - so maybe also try that at some point to see if you like it)
And second, which kind of glass is best to use with ice? Can it be used with any bong, water pipe, or hydratube?
Technically any piece with a big enough mouth hole for you to jam some ice in is suitable.
If you have a piece of glass with ice pinches, then the ice will be held up out of the water, and will cool the hit after its passed through the water. As the ice melts, the water level in the piece will rise a bit.
If you have a piece of glass without ice pinches, then the ice will most probably fall into the water. In this case the ice will melt quickly, and the hit will be cooled while passing through the extra cold water. The water level will jump up as soon as you put the ice in, but not much more as the ice melts.
You generally want to be very careful using ice with hydratubes, as they don't have much leeway for rising water levels before they spill back down the internal stem.