I've seen up to 12 on good clear days. Just bought this GPS shield and will install it over the weekend. Haven't been able to fly here for a few days because of really nasty weather. Once it clears I'll take it up and see what it gets after the shielding.
On another bird I have that m8n puck and Naza Light and it sees sats even when indoors. Outside it's common to see 17-20.
My previous quad would only get around 8 MAX but that was before GLONASS was added. Right now I see a min (outside) of 11/12 and have seen as high as 20. I don't pay a lot of attention to how many so those numbers may not be "average".