The mantis is one of my favorite discs, I love its versitility (167 gram Elite Z) .  This was the first fairway driver that I ever purchased, and I still have one in addition to the ace race prototype version in my bag.  The Mantis is a straight shooter for my RHFH throwing style.  Slight turn and fade are noticeable, but you can throw this thing on a frozen rope that barely moves laterally.  I feel that the fade rating of 2 is too high it should probably be 8/5/-1/1.  I use the Mantis for all kinds of shots, it is one of the few drivers that i can throw backhanded with confidence.  It is also great for tomahawks and thumbers ( flies like a hammer throw from ultimate or catch frisbee).  However the mantis is best used as a driver for precise forehand flicks, and great for threading the needle on heavily wooded holes.  The mantis can hold most lines you put them on, when i dont know what to throw i usually end up reaching for this disc.  Flies very well when powered down, allowing you to use the disc in a variety of situations.

 The original prototype I have flies true to the listed flight numbers(8/5/-1/2), which makes it more predictable than the current model as others have noted.  If you can find the 2013 ace race version, grab one, as the extra stability is nice.  Both versions will have a spot in my bag for the foreseeable future.  Great disc for all players who dont have cannon arms, highly recommended