You know, an Akira Retrofit would fit thanks to a simple argument. We already have the Excelsior and the Nebula at Tier 5, why not the Akira? Following the tradition of those 2 ships, the Akira would be a Fleet Escort with a Lt. Com Eng station. Simple.
As for Cryptic designs. I actually like the C-Store Star Cruiser + Emissary saucer. I'm also trying to find a good looking Fleet Escort since it is my favorite escort layout, but everytime some little details screw it up, often those little wings on the top. I whish the design was more towards the Intrepid Type from Enterprise. The newest C-Store ships are nicely modelled, but I have to say, I hate the T2 Escort Refit, this ship is just plain ugly.