White thermal paste vs Arctic Silver?

I'd normally use Arctic Silver on everything too, especially since when I tried some cheap white paste years ago, it didn't work as well. But I'm wondering if Apple had some reason for using the odd spongy white stuff I'm seeing on the VRAM chips. One guess is that, since VRAM doesn't get as hot as the GPU, it may not need the better, more expensive stuff. But since I'm replacing the dried-out Arctic Silver-like paste that Apple used on the GPU, with actual Arctic Silver (which may not be any better than the gray paste Apple used), I figure if it can't do any harm, I'd replace Apple's white paste with Arctic Silver too, unless there's some reason not to (which I can't imagine, but I've been wrong on something once before).

I just wouldn't use thermal paste of RAM. If you're really worried about RAM heat, try using heat sinks made for RAM. You can get these for like $1.00. Here's a bunch: http://shop.ebay.com/items/ram%20heatsin...