Multishot being 20 hatred with the rune means that it's not horribly more expensive than rapid fire, but I'm not sure I'd use it yet at that level. Rapid is 220% as physical (compared to 165), or fire with the withering fire rune which also reduces the initial cost to 5. You could caltrops and then sit behind them and pretty much clean up that way. Multi might be better for mobs, but it's a high price to pay for the reduced damage potentially.
Unless multi pierces, in which case the damage multiplier gets intense pretty quick.