Wouldn't a Marilith with 6 Speed Longswords be awesome!?

[Innis Cabal]

For the same money (well actually 6000gp more) you can get 2 Bows of splitting and speed. Give those to an arrow demon with 16 BAB and improved rapidshot and you get to roll 24 times on a full attack action. See how long it takes to drive yourself nuts.

Considering normal party comp? Four to six times.