I tried flanking Onslaught with a Heron. At 130 with zero-flux speed bonus, it has trouble flanking Onslaught. It could do it, but not without taking some serious damage. With bonuses from Helmsmanship (for 138 speed), Heron could flank Onslaught a bit more easily. Later, I tried to flank a Dominator with the same Heron but could not do it.
Odyssey with 80 speed would have enough speed to withdraw from things that threaten it, and maybe murder some of the slower cruisers and destroyers. I doubt it will be able to run rings around capitals unless it gets Plasma Jets like Aurora. Now, Aurora is a speed demon with Plasma Jets. It will run down and catch destroyers, even Medusa. It can come close to Heron at killing a fleet, but Heron is still better.
Odyssey should keep its 0.8 shield. 80 speed should prevent some cruisers from kite-and-sniping Odyssey to death. Two fighters should make beams a viable option for Odyssey too, although no more OP for fighters when it already has a slight OP shortage makes it less than exciting.
If High Energy Focus would be replaced, Reserve Deployment would be fun to spam fighters when needed or maybe to keep up with Legion.