I can understand you not wanting an induction kit, but I can't see the point of getting one of these panel filters. You've got a high performance car that's had thousands spent on research and development of the standard airbox that will perform as best as possible in terms of cheap and readiness of replaceable parts for manufacture and consumer.
The only point in changing the filter, IMO, is to get performance. The only way to better the OEM setup is to go full induction kit.
I've got a FL Cupra, replaced mine with an induction kit, started using V-Power and it made a huge increase in power. According the the rolling road anyway. I know they can be a bit of a lottery.
Mmmm, not being funny, but that would surely make your first statement pointless, because if all this money was spent to make it so great to start with, why do we all think we can make our cars better with items like filters/induction kits, remaps, lowering etc etc?
Ultimately, I bought the car, it needed a service, and this was bought as a replacement to the original.
It will, as it has always been (apparently), be run on the highest octane fuel.
I personally don't want the additional noise of an induction kit, as to me, it's as irratating as a dump valve (I thought I wanted one of those years ago on my Focus RS, and it was fitted on a Friday and came off the car on the following Monday!), if my car gets remapped, it will only be to stage 1 anyway.
When it comes down to it, it wasn't naively bought for massive, or indeed any performance gains, it won't harm the car, so it was done.