The only 1:9 bikes I've built thusfar, was (don't laugh) the old Protar stuff. That was quite nice to do. And the bigger bike does look impressive - just don't display it with your 1:12 stuff!
I suspect the bike portion of Protar is what is now the Italeri bikes. So to answer your question, I have not built one, but if it actually is the Protars rebranded and they kept up the quality and detail, I'd almost certainly try one myself. Except the mrs will kill me if I pitch up with another kit on my to-do heap at this stage!
But that price seems a bit steep. I can buy it locally for less - and I almost never buy locally due to it being so expensive over here (in South Africa). Shop around a bit, I'm pretty sure you might be able to find it cheaper somewhere. Tried HLJ yet? I know they stock some Italeri.