IMO, it's all bovine excrement. Ask yourself; what is dry aging? What does it accomplish?
I did dry age a prime rib roast last year. I started with around 7 lbs, and after 30 days I ended up with around 3 lbs of usable meat once all the dried bits were cut off.
There is a reason that dry aged beef is expensive. It's because if you buy 100 lbs of beef at lets say 200 dollars, and once you dry age it you end up with 60lbs of usable meat, your price per pound has increased.
I've tried the UMAI bags, and they are extremely expensive for what they do. As for that Steakager...you'd be better off buying a small bar fridge for a hell of a lot less money and dedicating it to aging meat.