I have quite a few knives but none from Mantis. I have, however, handled them and talked to a friend that has one and likes it. I never really cared for the design of them. They look all cut up like they went out of their way to try and make them look tacticool.
That being said though, the two models you mention are very nice. I like their look and design. The steel that they use is very good (on the CM model anyway) and the blade design is pretty decent too. The tire rubber handle should allow a really good grip, even when wet. The only thing I am not sure about is the jimping on the handle. I wonder if it will rub your hand a little too much during continued, hard use. It probably wouldn't be an issue since this size of knife isn't going to be a chopper or anything.
The sheath looks nice. Their headquarters is in Cali but that doesn't mean they are made in the US. Still they are probably worth the money if you like them. I would be interested in your review. I really like knives as well as guns and always want to learn more.
This looks like a pretty good deal but isn't the one that I would pick out of the two you are looking at. The 420 stainless isn't "premium" but if it isn't going to see hard use, it would be fine.
http://www2.knifecenter.com/item/MNTTA2/mantis-ta-2-seymour-fixed-3-inch-skinner

 

I'm not to big on the tacti cool crazy looking ones myself and mostly favor fixed blade knives. I like a knife I can USE (lol) for almost anything not just one function, like my K-Bar TDI....it really only has one function. Just recieved the Mantis TA-2 Seymour today. So far I am impressed with the knife as a whole but there are no "made in ...." markings on it. Still trying to find if its made in America. I'm reading / hearing different reports and will probably just end up calling them. Have not put it to good hard use yet but a full tang, 3" blade, sharp as all heck and able to shave my arm hair knife looks promising. The tire rubber (ZR rated...kind of funny) seems good but does not cover the whole handle. I can feel the edge of the metal dig into my hand a bit but love the full grip I can get on it. Fits the hand well but I'm thinking removing the rubber grips and doing a para cord wrap. For 25 dollars its going to make a good strong truck knife or a quick day hike in the woods type of knife. Maybe even a back up / self defense knife. I really want to see how it does on a deer, it seems it would be great for it. Now if I can get a deer lol. Last few years I have been striking out. The knife looks very strong at about an 1/8" thick and the sheath has a good internal lock with a good clip on the back . Because the sheath is interchangeable carry I'm able to carry this knife vertical or horizontal. Would like to get their Principle knife made from the 154CM steel, but need to spend the money else where right now. All in all this Mantis Seymour knife that is about 8" long overall is a pretty good well made knife thats is well worth the money.

 

Ok ...a two week update. Removed the tire rubber all because I did not like the sharp edges on the tang or the rubber itself. I probably could have also filed those edges but went a step further. Got rid of the rubber grips and did a paracord wrap, don't think about reusing the grips after you remove them. They were molded together somehow (maybe dipped) / attached by the tire rubber to each other, so once you remove them they are off for good...unless you want to use some type of adheasive lol. My vise was being used so I did the wraping without it and didn't come out half bad. Could have been way better but its good for now. Filed the sharp edges around the tang / handle before the wrap.
After wearing this knife for a while now I am see that the clip is not all that I thought it was to be. Could be my thick belt but the clip does not seem to grasp that good. Its week imo and would not trust it if I was running.The hold of the sheath on the knife itself is ok. If I was to quickly jolt / shake the sheath with the knife in it, it will start to slide out. Useage...Its a sturdy strong and tough looking knife but haven't given it much use. All due to me not getting out in the woods and do some camping or hunting, or any need to use it yet. Looks like this will be heading to be one of my pack knives or a good truck knife.

 

Got any pics of the wrap? Are you going to have a sheath molded for it?

 

I'll get some pics up tomorrow, its not the prettiest but will do for now. When I get the vise free I'll do the wrap better. I'll have to look more into sheaths, I'm not to well versed on making sheaths for knives. Looks like If I take a dremel I can make the slots on the sides of the sheath longer to fit a belt through them. I still may have the issue of an accidental fall out. Maybe I can call Mantis and see what advise they can give me on how to make it a bit tighter. I know my Ka-Bar TDI sheath is great for holding in the knife. I have no worries with that one or with the clip on the TDI sheath. Same goes for my CRKT and Gerber kinves. I understand they are a small company (compared to Buck, Gerber, etc etc) just getting off the ground. There will be some small issues to deal with so this really doesnt bother me much...especially when it was only 25 dollars shipped and no store had them around here. If it was a well established company then it would bother me.