Here is a video of the initial tank filling for the leak test. I have a laundry tub right next to the sump so I just ran a tube from the faucet into the sump which pumped the water into the display tank.
I think it is a great job. I like the second one much better as well. My critiques would be these:
First, the rock height is obviously a challenge for this tank which is understandable. Right now there are three structures though that seem almost the same height by the pictures (left, center, back right). Breaking that up a bit may be more interesting.
Second, the left and center structure are very similar. I would consider sliding them closer together to create one large cave structure. You could leave the other pieces as is and this could solve the first critique as well as the heights will seem less pronounced. I think that would bring everything together, but of course this is just my opinion for my tastes.