Dranko rocks!
Although oddly enough I don't have a problem with the lasher PrC despite the point of this thread....
Why is that?
Well, because the whip isn't really a weapon. It's a tool which can also inflict damage.
And when I think about the Lasher PrC I mostly remember "Third Hand". Which came what, 3 levels into a 10 level class? The rest of the class however is still not about somehow using a whip to lop dragons in half, it provides themantically appropriate abilites which are more about status infliction and control than raw damage. A lasher is never going to stand toe-to-toe with a raging barbarian in a DPS contest. And that's okay.
Suppose you had a "Shoveler" PrC.... If all it did was somehow try to turn something as stupid a Spetznaz throwing shovel into an awesome weapon of mass destruction, I would hate the class. If it somehow made a shovel seem more shovelish and yet also useful I suppose I would be okay with it, although it sounds like a dandy 3 level class, I don't see how you could get 5 out of it. And I would never be crazy about it.
And besides, as much as I love me some mystery men, a Shoveler is simply not high level heroism.
Man this thread is going in spirals....
Ok. Here is my position.
Single item centered prestige classes which do not represent a fictional or mythic archetype are bad. Single item centered PrCs that perform a useful mix of roles are good. Single item centered PrCs that desctribe a role or fighting style which is historically, mythically or ficitonally justifiable are somewhat acceptable, but I'd much rather see it done within the scope of the fighter class.
However for the most part I would must rather see item/weapon speciallization and skill building handled through the feat and/or powers maneuver system.
Arcane Archer is good. A non-magical archer PrC might also be acceptable, but I'd rather see it covered by the baseline figher/ranger. The Lasher is a cool PrC, but it could be done instead with a simple feat chain (Weapon focus whip, 3rd hand.)
A gladiator is not a varient or subclass of the fighter, it's a fighter. A retarius, secutor and murmillo are not sub-classes of gladiators, they are fighters. An archer, a lancer, a flamberge wielder, a lajatang wielder, a dragoon, a samurai, a skirmisher a landsknecht, a man fighting case or florentine. These are all fighting men, who make their living by trade in arms. They are fighters. Why would they need another class?