Yes, Microshift is relatively comparable to Shimano. They don't make really high-end stuff like Ultegra and Dura-Ace, but what they do make is very good, and well regarded for the money. Sort of the Hyundai of bike components.
Shimano's Tourney isn't bad-bad, but it's Shimano's bottom-end product.

Most of the components on the two bikes you're looking at are generic, so I can't really say what one is better, but one thing jumps out: The rear wheel : The DBack has a 7-speed freewheel with a nutted axle, an the GT has an 8-sp cassette with a Quick-release hub. That, right there is the quickest, most easily identifiable way to tell a 'cheap' bike from an 'inexpensive' bike.

If your budget can swing it, get the GT.