Frankly, bragging on 7 years of service and qualifying expert as “experience” with AR-15’s - which we also know would have been decades ago - is indicative that you really don’t understand the breadth and depth of the current AR market in 2021.

Among the AR market, Diamondback rifles are relatively low quality, low cost, low performance. It’s pretty hard to mess up an AR, and it’s not hard to make an AR shoot ~1moa (I’ve built over 600 which all do). They’ll go bang and feed most ammo - which isn’t saying much. If you found a Ruger American to be garbage (asinine, but it’s your taste), then you’ll find the Diamondbacks to be worse. There ARE factory AR’s which could draw my money, and DB’s are a long, long ways from making that list.