[gaoshan]

As someone who travels to China fairly frequently I can say I've found this site to be inconsistent.

That said, different locations within China have inconsistently differing levels of blockage (for instance, you can access many more places from within the greater Shanghai area than from within nearby Hangzhou and can find differences in what is available between Hangzhou and Beijing) so I think it is difficult to definitely state that this or that site is completely unavailable from anywhere within China.

[tnuc]

This is because of the different service providers and the decentralization that is applied from within the government.

It leads to inconsistency but it stops some of the mistakes that result from an overly centralized government.

[jacalata]

Lots of it is applied at province level, as I understand it. There is not 'one firewall'. That's probably why this site gives you a result for five different provinces.