Powermac, sleep or shutdown?

I have a powermac g4 cube, its on pretty much 24/7, I know that with a laptop, most of the time it just sleeps, how about a powermac, should I shutdown when Im not using t, or sleep it? sometimes I leave it on if its doing something, like converting video or something.:mac:

so when do I shut down, if ever?most of the time, I run big apps simultaneously, garageband, illustrator, photoshop, indesign, etc. it seems like my mac gets tired sometimes when I leave it on for days, after a restart or an hour or so break, its fine.