I own all three fates, Clotho, Lachesis and Atropos. I can't speak to their durability because mine are all collectors.
I purchased them because I like the blade design and overall looks of the knives, and also because of the high end materials used in constuction.
Overall I suspect they are very capable knives, however I do find the titanium liners are a bit flexible, not sure this would be problematic, and may well be a trade off between flexible and lightwieght titanium vs stiffer but heavier stainless steel.
The knife is comfortable in the hand, is lightweight and slim, and has a functional pocket clip. It should work well for EDC.
Blade deployment is smooth, but not as slick as my PXL or P/3G Fallknivens.
I did an "out of box" comparo between my Mercworx Lachesis and Fallkniven PXL. I'll see if I can search up the link, you may find some of my observations of interest.
If you really like the knife, you probably won't be disappointed purchasing one, but, IMO there are better folders out there for similar or even less $$.
Personally, I prefer my Fallkniven PXL, it is heavier and bulkier than the Mercworx offerings, but it is rock solid and instills a sense of confidence in the hand. All at about half the cost of of the Lachesis.
Kevin
EDIT: Here is the link -
http://www.bladeforums.com/forums/showthread.php?t=635342&highlight=PXL+Lachesis