I thought the parallel dimension as the source of issues the crew faced opened up possibilities for the plot rather than created frustration for me, the viewer.

Sure, there were situations that could have used a little more explanation, like the Russian guy and the gyro, but I don't think it's terrible that we don't know why that happened to him.

It wasn't San Andreas levels of stupid-action-flick, but we didn't get The Prestige levels of depth. I was happy with it, but did feel like the Cloverfield monster was kinda shoehorned into an otherwise decent plot that could've survived without the Cloverfield ip and with a little more exposition.