Millions of years ago in the futures past I was full-metal J-man and left my boxen on for months at a time. That said, 2014 Venn has SSD drives in spooky RAID and my box makes with the desktop in +/- 13 seconds from naught.
My netbook stays up for months at a time… Cuz its so damn slow to reboot. Every once in a while I leave it in suspend too long and the battery trickles out like a old man’s piss.
My laptop will stay on for a week or two, sometimes. But truth be told, ever since I got both SSDs running on it, it doesn’t even take 15 secs to load my KDE desktop.
There’s no point anuymore, really. Unless it’s a server!