Note that faster doesn't equal more accurate and that there's always the issue of routing and distance. This is why individual tests may be more accurate than testmy.net, but it's certainly not that common. It can still be said that testmy.net has the most accurate results on average, or else CA3LE would be back to working on them.
raptors892004:
Full Duplex: Data can be sent and received at the same time
Half-duplex: You can only send or receive, not both at the same time.