Of course, nobody really cares all that much about a heron's stats, right?
Personally I prefer Rafiel for endgame. I don't find myself willing to give up one of Reyson's moves to use a Laguz Gem or something except on 4-E-1 and 4-E-3. And if he uses a stone on the other three chapters, he might not even see action. In endgame he only has flying over Rafiel, where Rafiel is, as you said, Fox, going to make Endgame much faster. Perhaps you prefer Reyson for flying over gaps or something, but there are lots of units to vigor and I stick the heron the boots and Celerity so they're getting wherever they need to be anyway. Plus Rafiel can have his refreshed units kill or block off what's threatening him so he doesn't need Reyson's Canto, either. And I don't think spirits are killing anyone, even him. So what's your reasoning for preferring Reyson? I don't quite understand.