Pretty much all aftermarket spoilers are gonna have a blind spot, it comes with the territory
But if you really like it, then you should buy it regardless of the blind spot. You'll get used to after a while. For me, it took me about a week to get used to the APR GTC 200 spoiler. One good thing is that the spoiler will be high enough so that you'll be able to see through your back window. The stock spoiler is in a really bad place, IMO.