Surge tank? Hmmm. What controls the "dump trigger" on those? I get that basically a reservoir fills, then dumps at once into the tank, then refills...
Smart about the lack of gravel. I don't have a problem with shooting through plexiglass (my photos of Grant's corals are decent), just don't like curved surfaces for photography as they tend to introduce visual distortion. My issue with plexiglass is how much I love scrubbing the coraline off my acrylic flat compared with a quick razor blade or magna float on my glass tank.
The peninsula tanks with the curved ends are very pleasing to the eye and the store looked very nice.