Tenacious is a great knife *for the price*. If the tenacious cost 50% more then I doubt many would be so interested in it, a Chinese made knife with low end blade steel for $60 isn't very appealing.
Manix 2 is incredible for the price, and at 50% more would still be appealing. For $120 an American made knife with ball lock wouldn't be way out of line.
At current prices, I would much rather have 1 Manix than 2 Tenacious for the same $$. The new Manix is ranking right up there with my ZT 0300, Hinderer XM-18, and D2 Paramilitary as favorite EDC's, and it's far less expensive than any of them. All the Tenacious I have purchased have been gifted away as I never carried them. I bought them because they are great knives for the price, but nothing stands out about it as being very special compared with other knives (besides the price)
Manix 2 stands out from the crowd, IMO.