Let me preface this by saying, I haven't used either one! lol Sorta.... I own the M2 ,which is theoretically the little brother to the v7. All the Hapstone sharpeners are built like a tank,for many years of service. My m2 doesn't have removable magnets, but I wouldn't take them off anyways. it does however have a blade support on front to make sure knives dont tip when moving the slide back and forth, which I love!
They all use edge pro size stones and can use kme size too if you had some around. So, the choice is whether you want a clamped style holder or not. Some of that would be dictated with what size/style knives you need to sharpen. I would think if you are doing swords or the like, it would be easier on the V7. If you are doing folding knives, fixed blades under 12 inches, etc the K1 would be easier.
If you like the rotating clamp style, the K1 is sooo cool. But! I will throw this out there in case you havent seen it.
Gritomatic does this thing that I'm not sure is a good idea, but its the most honest way of showing you whats in stock or not.
By that I mean if its not in stock they dont show it under sharpeners. I'm referring to the R1 . Didnt see it? yeah, its sold out so they take it off the sharpener page! What!!?? It isn't on the Hapstone sharpener page, but if you go to the front page of the website you can see it. Heres a link:
https://www.gritomatic.com/products/hapstone-r1-knife-sharpener
Of course, more money, but it has a much more robust clamp, for heavier knives, and this guy has every single option built in from day one!
Micro adjust, conpensators, list goes on. I have added stop collars and thickness compensator to mine and while they are priced reasonably, but the R1 has it all from day one. If I ever (I always do) move on to a different sharpener, it is the one I will go too. That being said, I in no way regret not waiting to get it cause I can get awesome edges now.And I dont know how soon they get restock on the R1 either, so there is that...
Flipping the blade by hand is not that big of a deal to me , but yeah, especially if you have multiple knives to do or have one that is gonna take alot of work, the clamping style has a real appeal to it. money and options...