I disagree. It depends on what you want to do with it, really.
Swordmasters are amazing units; S5 ASF weapons that can even parry ranged attacks. Seaguard are, for a troop, fairly elite, though honestly they're better used as basic Spearmen. HE Spearmen can attack in four ranks, and always strike first. Seaguard are the same thing, but also have bows.
I've never played with the gryphon, so that's the only one I can't really comment on.
As for Reavers, they are deffinitely a playstyle that you need to want, but for Fast cav they're pretty strong, and you can give them bows and/or spears, making them strong harrassers and bait.