Not tall at all, really. I think the short height of the doors makes it look taller than it is. It's gotta be more stable than that other stand. Good job!
That is why I built my own stand using 2x4's. Those wimpy tank stands just don't make sense to me. I'd always be wondering if it will support my tank long term. Imagine 70 gallons of water across your floor or worse. I would definitely reinforce that stand and make it level. 700+ lbs of weight! You can't can go wrong reinforcing it. You could go terribly wrong NOT reinforcing it.