I actually own several of the Mantis karambits, and I must say that this is a cheap, but efficient cutting tool.
The lock-up is actually better than some of my higher priced models. But,
if you're looking for this knife to be a SD edc knife I suggest that you put it in your pocket, have someone walk toward you at 20 paces and draw.
You'll quickly find yourself fumbling to get the blade open and into a reverse grip.
i.e. if your life was in danger you'd already be dead!!!
The knife that you carry should be functional, fast to action, solid, and comfortable.
I can tell you from experience that the Mantis tanto kara fits almost none of that criteria.
Even their better models, (MK 1/ MK3) cannot be deployed fast enough to be carried as a dependable SD tool.
Perhaps you should seek some formal blade training to help you find a knife that suits you.
I know guys that carry everything from Sharpfingers to bowies all due to their comfort level.
If the karambit does float your boat, might I recommend either the 5.11 tac Masters or journeyman, Emerson (if $ is no option), or go to
www.traditionalfilipinoweapons.com.
They have a Karambt made from 5160 thats awesome.It'll cost around $160.
If you must go with a Mantis knife get the Seymore.At least you can augment the clip to make it deployable from various positions.
Good luck, hope you find the right knife.