[Rathji]

I never turn any of my computers off, except my laptop when I travel. You need to be sure there are no overheating issues, of course, but you should be doing that anyway. The only bad thing about leaving a computer on is power consumption, Over the long run, you will save money buying a new router. You might experience sluggish operation due to memory leaks that exist in many programs, which would require a reboot to clear.

If you don't need to use it, there is no harm in turning off the computer, unless you really mess up the settings for sharing, it should be persistent.