the creation TIP reduced very early on Paul, the forge one is 70mm at the top and gradually tapers down, only reducing fully at the very bottom where space is ultra tight.
The creation one is 70mm at the top (for the MAF), then reduces gradually to the first bend (near the DV port) but from here down it's ALL tiny to the turbo. Holding one or the other in your hand you often won't spot the difference, but get them both together side by side and it's really obvious!
I showed an S2000 owner at Donington my air filter yesterday, he honestly couldn't believe I was running it, and was even more shocked when I said it was happily producing 330+ bhp with that filter on there!