i picked up power at my level with an open cone over my wizair set up. its not that its a restriction, its that your getting more air allowing you to make more boost also.
what ever makes you sleep better at night, go that route. plus intakes are easy to swap around, try it for yourself, you might get different results from other people.
i like the open cone, its loud, it suits my needs. everybody had different needs out of there car.