I don't know of this is too late for you, but I can give a quick review. The noise isn't significantly louder than stock. The most notable difference is the diverter valve is slightly louder. Not loud enough so you'd hear it outside the car, but inside there's more of a chatter. There is a noise increase but it is limited.
While I'm at it, I'd also dispute that the Carbonio doesn't increase performance. I (and also others on the net) have logged MAF and there is a measureable increase in airflow just from adding the Carbonio even without the filter. All up with the Carbonio, Pipercross filter and about an hours worth of modifying the airbox and turbo inlet pipe my MAF has increased from 252g/s to 273 g/s with perfect LTFT of between 1.3-2.7% compared to my full intake which was loud, defectable and dropped MAF from 252 to 233g/s with haywire LTFT around 7-12%
Michael.