Neither blade especially appeals to me
The MLEK has a recurve to it that I don't care for.
But, I've read several positive reviews of Blade-Tech products.
The MLEK series knives are made in Japan IIRC.
The Investigator appears to only be available in a combo edge on either a tanto or spearpoint blade. I don't care for combo edges. I don't remember reading any reviews of their products, so I am unsure of the fit and finish. The knife is imported, but I don't know from what country.
For me, between these two I would choose the MLEK. The recurve is slight and I will take a slight recurve over a combo edge, plus the quality is less of an unknown. YMMV. If I could get the Investigator in a PE I would risk the unknown quality factor and go for that. Better steel, better blade design for what I want in an EDC. (note, in my own manila rope cutting tests, ATS-34 was a goodly notch above 440C in edge retension. )