In response to the comments above, depending on how a carburettor'd bike has been set-up, rejetting may be required. However this certainly isn't always the case, and varies from bike to bike.
On all newer fuel injected bikes, no setting up is required, as the ECU will automatically adjust for the increased air flow.
Why don't bikes come with high flow filters as standard? Simple. Cost. A performance filter is far more expensive to produce, and manufacturers will always build to a price.