What bitterness scale do you use?

A discussion in another thread got me to thinking. Someone was saying they like way more bitterness for a certain recipe. It finally came out that he was using Rager and I always use Tinsteth.

Out of curiosity I changed the setting in my brew software for one recipe and the IBU's went from 30 Tinseth to 41 Rager. Big difference.

Since I have always used Tinseth I am used to it and am comfortable using it.

Which do you find more accurate?

I have been using ProMash for quite some time, and the default is Rager. I have never changed it, and feel comfortable that its IBU calculation closely matches my perception of the bitterness level.