I bought it and played it for a couple of days, but found it too repetitive and slow paced, the violence was gratuitous, but not enough to keep me interested, so I lent it to a mate.
If sneaking around and killing people is your thing then consider thief or splinter cell, they have much more to offer.
ive never played manhunt but have heard many poor reviews and no good ones so my advice would be dont bother.like the previous poster said,there are far better games out there in this genre