Good Machine
I have a 15" MacBook Pro from 2006 - Core Duo 2.0 GHz. It is what you would call my "pride and joy" I guess.
Let me give you an idea of how I have used my machine:
I used the computer in engineering school and I lugged it everywhere for programming in unix, and various windows programs via parallels. I would use my laptop instead of the computers in our labs. There were a couple of times (while unix programming) that I accidentally put the processor in an infinite loop and the computer got very, very hot.
For 3 years I used the computer every day for 8-10 hours. I would play DVD's on the computer from netflix in the background while studying or programming (ie House MD - great background series) to keep me motivated. I also scored (original sound track and foley) a 2.5 hour film and various small projects, so the computer would spend several hours encoding with the fan on max and the processor temp hovering around 200F.
For the last 4 years since graduation, it has been used 1-3 hours daily at home while I suffer using a PC everyday at work; a PC that has to be re-loaded and I spent 3 days re-installing software and setting it up.
I have replaced the following:
3 Batteries at 2 year intervals (old li-ion tech)
1 Power Cord at first year.
One DVD Drive (after watching about 1000 movies plus software and burning cd's)
Both Cooling Fans @ $50/each (after 6 years heavy use)
Never re-loaded OSX, upgraded to snow leapard
Upgraded HD twice using the time machine backup, flawless
It's still running just fine, but is considered "vintage" and not longer supported by apple - so at some point there will be some software that will force me to upgrade. For now, I'm holding out for Flash memory pricing to keep on falling.
Only trick to regular hard drives is: After closing the lid, do not pick up and move your computer because it is trying to write data to the drive. Wait until the sleep light is pulsing. This keeps the bearings on the platters from wearing out from the torque applied to the axis of the platters; eventually the head will make physical contact with the platter when the bearings are loose enough.