It only does good damage with very high PS and a good speed bonus, against someone who doesn't know to block or still gets fooled by the jump swing trick. If I deal so much with it, it's because of my PS and the speed bonus I get when jumpswinging (you're moving towards me, weapon sweetspot = very high speed bonus). I don't see the point of making it unusable on horseback either, it's very slow and 14p, so you're not going to kill anyone using it on horseback.
I'd rather increase the price to something like 1k5-2k and keep it the way it is. It's the only really long polearm in the game with side swings ( since long voulge has been nerfed into utter uselessness for no apparent reason), nerfing it's stats would make another playstyle useless. Unless you add a new slow and expensive polearm with a long length and side swings, that would be a little bit like the polearmer's flamberge (longer but with less damage).
The main issue is probably with strategus, so that's why a cost increase should be enough.