The hardest thing for someone who likes to tinker with their system is to
leave their system alone long enough to determine if everything is O.K.
Test run your system " AS SHIPPED " before you add ANYTHING.
Do not add RAM or Software OR any third party anything until you know
your basic machine is trouble free.
I would give it at least 24 hours without any shutdowns.
If you plan to partition your drive (s) or plan to re-install the OS
in a Custom lean install, this would be a good time.
Go to Applications/Utiliities/Disk Utility to set up your drives.
Run the hardware test CD, Set up your accounts,
one for Administrative ONLY and one SuperUSER for daily use.
Once you're up and running, it's time to download all the Mac OSX and application updates using System Preferences/Software Update.
You'll need to reboot a few times to activate some of these updates and that will also tell you if there are any problems.
At this point there should still be nothing on your machine that Apple didn't
provide.
All your Hard Drives and partitions should be showing on your Desktop.
If you purchased addtional RAM, now you can carefully upgrade your machine.
This step by step method helps you determine the cause of any problems.
If your system fails to boot or starts getting Kernel Panics after you install
RAM, you know what probably caused the problem.
Generally if a machine works when you buy it and keeps working trouble free
for the first 6 months, it will probably last forever.
Unfortunately, individual third party components DO fail.
Hard Drives, Optical Drives, Video Cards and RAM are easy to replace, but the cost for just one simple repair can exceed the cost of AppleCare.
If your business or personal life depends on that machine, I'd say that AppleCare
is worth it.
These are still new machines with a bunch of new components that may or may not develop problems over time.
The faulty 3rd party capacitors in Rev A iMacs did not show up until those machines had been in use for roughly 6 months.
The heat gradually caused those capacitors to fail.
One of my best friends has one.
Apple has already replaced his motherboard 3 times and because he purchased Apple Care and kept good records, it looks like he'll be getting a new Intel Core Duo 2.0 free this month under warranty.
Are you feeling lucky?