Arctic Silver 5 or Arctic Cooling MX-2 paste?

And I had read somewhere that MX-2 paste lasts for up to eight years, and that Artic Silver should be reapplied every six months to a year. 😵 Hmm... Others?
 
LoL my sisters comp that I built using my leftover parts from my previous build has an old hot AMD +3400, which I took the heatsink on and off a couple of times, and is still using the same nasty TIM pad that it originally came with about 3~4 years ago. Idles at about high 20's low 30's.... I think I broke about every TIM rule there is but it still does alright.
 
MX2 is the best thermal paste at this point in time!
I have used both and after using MX2 i prefer it.
As the package says"8 year durability!"
non bleeding, NON-electrical conductive and "metal-free', non corrosive, non-capactive (a biggie!!), non-curring.
Do not remove and replace your coolers every 6 months. you're flirting with problems and damage to your attachments.
It's a falacy!