The only thing modern folders have going for them is the one handed opening. I prefer traditionals and SAK's for the thin blades that just seem to cut better. I really like the SAK because you can totally waste the edge but it'll still cut because of how thin the blade is.
Personally I believe everyone's first knife should be a slippie. You'll learn to use the knife properly. When you use a knife properly, you'll find there just isn't any need for a locking blade.
I quoted this post because there wasn't a "Like with extreme enthusiasm" button, or a double like button. Says it all very well.
I'm an old fart. I'm getting to be a very old fart. That means I've been around to see a lot of things come and go. I grew up in a time where mostly ALL men had a knife on them if they were dressed and had had pants on. It also was a time of more hands on work with a much larger agricultural society than now. Now the majority of people are employed in office type of environments, big box stores, and a more controlled environment. Office cubicle workers are very often under company rules as to what can be carried in the work place. Even stock clerks in big box stores get issued a safety cutter type of utility knife that does the job just fine.
What does all this rambling mean? It means that as our society changed, the cutlery industry was fading because more and more people didn't really need a knife in their daily walking mourned life. So, the cutlery industry invented a whole new demand. They brought about an artificially created need for a "new" style of knife and with hype and advertising fed the demand. The birth of the tactical knife. The one hand opening was hyped as the best thing since sliced bread and the match. I watched it all with amazement. With the right advertising you can sell anything. Cars with tail fins that look like would be rocket ships, clothing styles that leave a great deal to be desired of comfort and practicality. Knives that have little other purpose than stabbing or opening with one hand in a Hollywood manner. Never mind that the majority of them will have thick wedgie blade profiles that stop cutting well when the edge gets a little worn. Or that none of them have a choice of smaller blades for fine work or back up if one goes dull.
Being an old fart, I've had a varied life. I've been a outdoorsman, soldier, construction site worker, machinist, soccer dad and harry home owner doing repairs and maintenance around the house. Now I'm just one more retired old fart fishing along the bank of the san Gabriel river. But being retired I'm doing more fishing than ever before. Saying all that, I can't recall a single time in my entire life when I was imperiled by having to open my pocket knife with two hands. Convenient? Yes it can be. But at what cost?
Having grown up with multi-bladed pocket knives like jacks and stockmen, (we won't even go into how handy a SAK is) I tried the famed Buck knife when they first came out. Had it for a few months before I gave it away. Having a knife that weighed in as much as a small boat anchor with only one single bade seemed not only limiting, but ridiculous as well. The big clip point blade of the 110 seemed just too big for most of what I did. Opening my mail with one was an exercise in over kill, as was cutting some cotton or jute twine, trimming some fishing line, opening a box or many other things. But what really bugged me about the then new modern knife was, the total lack of picking the blade for the job. There was jus that big semi hollow ground blade that every other job was shaped wrong or awkward. It lacked versatility.
The stockman, jack, pen, all had choices of blades to choose from. And they had been used for a very very long time by working men who needed a real world cutting tool. Of the knives shipped west between 1850 and 1870, the Russell Barlow was the single most popular pattern. The John Russell company couldn't make them fast enough. They were sold at general stores in town, trading posts, and suttler stores on army posts.
Go ahead and use the ever lovin' dog poo out of your slip joint. It's made to work for a living. It was used for well over a century by men who were not knife nuts or collectors, but miners, cowboys, freight wagon drivers, and sailors who just needed to cut something in the course of their day. Drop a slip joint in your pocket and go out and live your life, and you may get a surprise. Those "other" knives are not really needed at all.