I don't think you are expecting too much from production slip joints (or any other production knives).
It is not like real quality, or consistency cannot be achieved.
I won't mention the brand, but a while ago I bought two locking folders. Fit and finish was excellent. Shiny, tight, no gaps in the handle material. Just one problem, the locking design was defective. I don't mean my particular one was. Come to find out, they were all produced with a glaring design flaw, but you had to use the knife for some time before it reared it's ugly head. Sent the knife back, and got a brand new one, on only to discover the exact same design flaw. Pretty ticket about it, to say the least.
For the price, I could have bought any number of real quality production knives without the flaw. I have other's from the same company, with that design flaw completely fixed! It is a very simple thing to fix.
Weak springs, bad fit and finish, poor edges (uneven, dull etc) would be expected in a 10 or 20 dollar knife. I do not expect it in a 100+ dollar knife.
A perfect example of how it can be done is looking at many import knives. China, Taiwan, etc can produce an in expensive folder with great fit and finish (look at AG Russel's drool inducing slip joints and locking folders from Chinese manufacturers if you don't believe me). They look great, and at a very great price point (cheap labor etc helps here).
It is very doable. I don't mind paying more for a knife with the same level of fit and finish made in the USA. I can, and will do so (as will many other buyers).
What I won't do, and don't accept is paying double or more, and receiving a knife with huge gaps in the scales, poor fit and finish, for that much higher price point. Not when I can pick up a Chinese knife with a much better fit and finish for 1/2 the price.
I will pay 150 for the American knife, when I could get a much cheaper, and just as visually appealing knife from a Chinese maker.
Just something about seeing that tang stamp. Especially when you hand one to some one to use, and they say "they sure don't make them like this any more". Then you can reply, "they sure do!"
Don't get me wrong, I am not a "built in the USA or it's crap" kind of guy. I don't think that about cars, or motorcycles, or bikes, or any other number of products (having owned, used, or even driven some real garbage built right here in the good old USA"
I just ordered a handfull of US made slip joints. If any are poor quality from a fit and finish category, I will send them back until I am satisfied.
On a side note, I am probably done buying products from the company that sold me a defective folder.............. It is not the fact that they produced a knife that had a design flaw. It is the fact that they did not make it right, and continued to sell all those folders with that same design flaw...........to unsuspecting buyers.
Just a minute tweak of the design completely solves the problem, but they were unwilling to do so on their stock of knives that had it. Just replacing one small part and bingo, great looking knife with an equally great working lock!