I considered the airfilter change for my bt-moto flash but went against it. Thing is, these sport filters don't stay as air-open, as it ages, it quickly plugs with dirt and it becomes akin to the regular already installed filter. You need to constantly clean it to keep the air moving, being the filter is hard to extract, I think it makes no sense to install it, it maybe give you like 3-6 months of more performance before it degrades again to stock. Plus, more dirt goes into the engine...
I think what I am trying to say, I am not fully sold on the idea. Maybe if it was a track bike, but on the streets...