So smootrk, the disadvantages of it being a 2 handed weapon with low damage die, low crit range, low crit multiplier, and needing a feat to even use effectively arent enough?
Even when someone could simply use a normal reach weapon most of the time to gain all of the benefits and more (no feat required, higher damage, can hit things at range, etc).
I see people complaining a lot about the power of the spiked chain and it always strikes me as odd. In just about every way it is a poor excuse for a weapon, except you are able to attack in 5' and 10'. A benefit that can be gotten by a simple first level spell or potion or a few higher level spells or by having a reach weapon and being able to take a 5' step or who knows what else, there are tons of possibilities.
I have seen it used in my game once, but the player gave up because of his lack of damage with it (tried the finesse route, but between the various methods to ignore reach and its low damage die + low str he just couldnt do much with it) and have seen it used in other games once (this time it was my own character, high str, and a few nice feats.. it was fun, but once we got past the goblin stage of the game I really wanted my feats back and a different weapon).
It is a good weapon with interesting options, but to me it already seems to be on borderline underpowered for the cost.
If you assume that being able to attack both at 5' and 10' is worth a single feat (which seems pretty reasonable to me really, I believe there is a feat that allows one to use normal reach weapons in this way somewhere) then the weapon simply has a few nice benefits which counter its other drawbacks.
Also note that you can only get one aoo per round against a guy who moves through multiple threat spaces of yours.. they could run around you in circles and only provoke one.. so the comic above is a bit misleading