For general use sharpening, lanksy and spyderco will fit the bill. Owning a spyderco myself, I’m fixed to 20 or 30 degrees, I had to find a system that can get me down to 7-8 degrees with accuracy. Owning japanese cutlery, my spyderco wouldnt have given me the edge I needed. You also have a limitation Stones and lapping films, The systems mentioned above dont allow for precise sharpening and mirror polish hair whittling edges (at least within a reasonable amount of time - how much is your time worth?) many Knife owners love including myself.
But for basic sharpening needs that dont require reprofiling edges, lanksy and spyderco will do the job with great results.
It’s true, the Spyderco specifically and definitely will not allow for any mirror polish or edge reprofiling, and while, with time, the Lansky could achieve either, it’s a matter of a whole hell of a lot of time. They’re just great sharpeners. Though I would challenge that they both, very easily get hair popping results and the Lansky, with so many stone options, can most assuredly get you a mirror finish, if you’ve got the patience and time. I would also agree that my time is worth much too much to spend doing such a thing by hand, but I also couldn’t care less about such things, as of yet. I just want utility. So I guess it comes down to what it will always come down to, and that’s philosophy of use and wants.
If you truly wish to get into profiling of blades, which can be very rewarding and create a truly perfect blade for the individual and their own needs/wants of a blade, then you’ll need something a lot more industrious, something with a power source.
Many people do just that. I got one for about $30 a few years ago and use it to dial in the very precise scandi/zero grind edges on a couple bushcraft knives that I have. I don’t use the stones that came with the knock offs but I found that my smaller DMT diamond stones fit the arm perfectly and work well being 2” wide.