Aussie SPCRers: How accurate are Jaycar power meters?

[Firetech]

As the title states, has anyone compared these units with a known load to check their accuracy?

I bought one today and am pleasantly surprised to see how low my home servers start-up load actually is (73w Max draw and 56-58w @ 'idle').

Given that I will be using this information to purchase an appropriately sized PicoPSU & power brick while overseas, I'd like to know if there is a small or large error on these units.

I know the specs state "+-4% or +-10W" but.....

Thanks