For a Samurai, Haubergeon is only a marginal winner and that's because of the nature of two-handed weapons (Samurai are always talking about Haubergeon +1, too, which is a different kettle of fish entirely). For a Ninja, Haubergeon is essentially a WS piece that's on par with Shura Togi and, arguably, Koga Chainmail during the TP phase. For Monk, I'm underwhelmed. I see the possibility of this with Accuracy/Attack +10 being analogous to Shura Togi. It would produce a slightly better Howling Fist or Dragon Kick due to the STR, but Shura Togi is likely to remain on top for Asuran Fists due to the relevance of Attack in multi-hit weaponskills that do not have an Attack Bonus built in. And considering that we can use Kirin's Osode, which will produce a substantially better Howling Fist or Dragon Kick than either option (and recent testing indicates that Accuracy is not as relevant as we once thought for the first hit of weaponskills, which is the important one), I'm less impressed by going this particular route with Mirke Wardecors.
If we customize it another way, though, it could be good. I'm really not sure what to do with this. Prior to getting my Togi, I'd be pissing myself about this, but looking at the stats and having Shura Togi now, it's a lot less appealing than it would have been. I'm almost certainly going to get the Mirke Wardecors (the options for my White Mage and Bard do not impress me as both of those jobs get plenty of good body armor), but I've no clue what I'll do with it.