Just because they received a "F" rating, from the Better Business Bureau rating, doesn't mean that this is a questionable business to deal with. I looked up the complaints and there was only 4 negative complaints, I read them and nothing suggests this business is doing or acting in way as be dishonest. These complaints are probably very isolated, and are a very small percentage of their satisfied customers. Honestly 4 complaints from a long established business is nothing, and the complaints did not involve sales, like handguns or rifles. One was about getting range time during the holidays and the other was about limits on ammo sales. The other two complaints were not shown, and likely settled to the customers satisfaction.
The only question I would have is it appears they are charging sales tax to all customers. Normally online sellers only charge sales tax on items shipped within the state that the online business is located, in this case AZ. Also some businesses charge sales tax to purchases from other states, in which they have retail locations. I doubt this Scottsdale business has outlets in many other states, if any.
I would not hesitate to buy from them, except my Shield is now 15 months old.
Bob