Okay so I recently had a thread about custom vs production for performance and it seems that the production might have eaked out the win. ...
Hi. When reading your post, my attention was caught by the key word performance. My reasoning here all revolves around this.
I can only take my case and speak strictly for myself. I use my knives (mostly folders) in different EDC scenarios. I prepare food (I generally do my own lunch in the canteen) when at the branch head office; I cut various packaging materials (cardboards, straps, stretch and shrink foils, plastic bags, twines and cordages, etc.) when out in warehouses or production lines at suppliers; I do some cutting, minor scraping (and the occasionally prying

) work when busy in the small maintenance tasks in my house; I work with wood (cutting, whittling, carving, playing around, etc.), various cordages and food prep when out hiking/camping during week-ends

. I can safely affirm I make an average of 50 cuts/day on these mentioned various media.
Whats my meaning of performance? I want a knife (I have a weekly rotation) which is sharp, handy, easy, comfortable, safe and which can deliver the expected results for my own set target price. Since my knives are tool, they need maintenance (cleaning, sharpening, etc.) and I also consider my skills, my time and the tools I have/need for that, when deciding what to get.
Aesthetics and look doesnt belong in the performance box for me. If I can cut proficiently with something I consider nice or beautiful, thats adding on satisfaction, it's a plus, but its a different thing.
Given these pre-conditions of mine, I have - up to day - not found any real poor/subpar performance issue in any of the production knives I own so far (besides some obtuse or not so sharp factory edge). On the other hand, having handled a few of fixed blades customs knives, I can say I havent found any real outstanding performances in those I have handled and tried out, compared to the production ones I own.
Its a fact that, specially nowadays, manufacturers display industrial equipment and applied technologies which a few makers can easily reproduce in small scale (most of the so called mid-tech knives, in fact, outsource some of these processes precisely at manufacturers facilities). I feel I have still a plethora of good to great production knives which can fulfill my needs and wants at a price I can afford (always considering that my knives are tools which are subject to wear and tear, can get lost, damaged, etc.). Also, as a humble knives hobbyist, I am no ashamed in stating I am not able to tell when using my knives the way I do the differences between one steel and another

. I can cut perfectly with a 440 C and with a S30V or a D2 the same way. No way I can practically tell if the same steel has been hardened 58 or 62. I have chipped both actually

! I can instead perceive the differences in blade geometry, comfort of handles, easiness/difficulty of sharpening and I have learned, along the way, what works best for me.
Sure it is different for people who compete in blades sports of sorts or for those who perform hundreds of manual cuts per day! Their definition of performance is different! Half seriously, if I see people in factories spending such an amount of time in manual cutting of whatever, I politely suggest an efficiency project, either to automatize the operation or change the process design/flow. Sure enough I have pissed some knives enthusiast

!
So I really think it boils down to your definition of performance. What does performance mean for you exactly? What you need (and many times just like

) likely dictates the choice.
Last but not least, I think custom per se doesnt mean superior in any way. A lot of poorly executed and performing custom knives exist and, from my own little experience, its way easier to implement process control on an industrial process in a big production plant rather that enforcing it in a small workshop.