Restarting the computer (i.e. turning it off every night) helps keep it in shape, in lighter terms.
I don't know, but I've heard of slowdowns because people just simply hibernate their computers every night. If your computer is really that slow to turn on you may want to look into disabling startup programs or upgrading your computer if its that slow.
No no no, call me impatient but it boots really quickly (30 seconds) when I turn it off compleatly and turn it back on. Fact that Hibernate not only boots quicker but also loads exactly what I had on my screen before the hibernation.
Besides, its a BRAND NEW PC, it has i7 and 8 Gb of RAM, how the hell can I upgrade it more? Add unnecessary 16 Gb of RAM? :P