Hi LTurk,
They are both awesome systems, and I'm sure you'll be more than happy with either one. Honestly, both of them will get your knives equally sharp, using good technique.
What I like about the Kazak system, is their ingenuity with their accessories and I absolutely love their light system. They have a Hinged table accessory that is simply genius - the same unit is a magnetic table for small or large blades, and it is a scissors, chisel and other tool clamping system all-in-one. Very well thought out. The "UBR" version of the rack and pinion in their Kazak Pro Black has a very smooth action and is well made. Smoother than most other rack and pinions currently available that I have. The only "negative" I could think of, is the fact that the horizontal rod is one long single piece, so if you store it away in a hard case, you need a huge case to fit the length of the rod into the case. This can be seen as a positive too if you don't want minimal storage size, because a single piece rod is more rigid and your the straightness is guaranteed. Personally, I store all of my sharpening systems in Amazon Basics Medium or Small hard cases (depending on the sharpener size), and for my Kazak, I made myself another 8mm rod with a coupler so I can separate it into 2 smaller pieces when I store it in one of my Amazon Basics medium cases.
As far as the Hapstone R2 is concerned, I recommend this sharpener as the best value for money coupled with excellent quality. It's unbeatable for the price and it's built like a tank. Yes it has linear ball bearings for the rod to slide into, but the Kazak (having a nylon sleeve), has a smoother action. Both Kazak Pro Black and Hapstone R2 have zero play in the bearing methods used and both work equally well, so it will come down to personal preference. If you want to have more versatility in clamping options, then I would recommend not going for the Hapstone R2 Black, rather go for a Hapstone R2 Standard (add the fine tuner, spring stops and angle cube from Gritomatic yourself) and also order yourself a pair of Hapstone R2 Lite clamps also. The R2 Lite clamps are great for smaller knives. The double set of angled clamps on the R2 Black is nice to have, but not necessary. You can do the same with the single set of angled clamps that the R2 Standard has.
As far as I can tell, Gritomatic will soon have Gearconnect adapters to add Hapstone, KakBritva and other clamps to the Kazak system, so you can have the best of all clamp types with the Kazak soon. (They have "coming soon" listed on their site for these) They may possibly soon also have a light system for the Hapstone R2 and for some other sharpeners. Maybe email them and check with them when they plan on selling these. Having a light system mounted on a sharpener with the little floodlights that Gritomatic provides with the Kazak, is a game changer. This has become a must-have in my opinion. I never knew how much of a difference this made until I tried the Kazak with the light system. I ended up designing and making myself floodlight systems for all my sharpeners so I can swap out my Kazak floodlight to any of my other sharpening systems.
