looks to me like Katannas specifically put in for TP gain and SC opening with really really fast TP gainers.
Roughly same DPS (not taking the nice stat boosts into account) as the level 66 +1 katannas with Delay being way lower.
The stat boosts should more or less even out the differences for ws, between say the Fudo's (which out DPS them considerably) and "the twins" and the subtle blow bonuses kinda lend to the tp/ws line of thinking.
So roughly more SC's more MB's, cutting the ninjas base damage for the party to do more instead.
I use this katana in my off hand with fudo main and am very pleased with the results. The low base dmg of this weapon isn't a big factor when you're not using it main and can crit a lot. Without trying to boost dex, I have +40 thanks to things like osode, haidate and warwolf w/ max crit % merit. And btw Kisami, 12% haste isnt very hard to come by, you'll see the great haste NINs with closer to 20% haste.