Mantis shrimps are the sweetness. I really miss having one. I have only kept the smaller species, and g. chiragra, which is a medium sized prawn, but I think your setup is a little on the small side for o. scyllarus. It'll probably be fine, just my thought.
Personally I like the smithii's and the veridis. The larger ones creep me out a little... but they're all very cool creatures.
Happy Super Bowl Sunday! GO GIANTS!!