I have the pepr flipped the other way so I don't smash my knuckles
That leupold hamr looks interesting
If you have the newer quick release version you just flip the quick release handles so they face backwards. I don't hit my knuckles with mine. It works perfectly for this rifle.
I'd like the Elcan Spectra as well. But... there's always another rifle that seems to come first.
I went with the smooth tops for mine although the mount comes with both so you can add a fastfire II or whatever you want to the top. In my case when I get a Fastfire II it'll be going on my PS90 anyways so no real need for now. Plus I find I can still shoot both eyes open at 3x with the Fullfield II anyways. I had one on a Ruger 10/22 a ways back. I was fairly quick with it at 3x and both eyes open. Yes parallax but for that type of shooting it was fine.
Here's how mine is mounted. You want the quick release lever just slightly back from where the charging handle naturally rests when all the way back. The handle will actually go back a tiny bit more. This way your lever ends up perfectly lined up with the charging handle when it is truly all the way back.
I really like the quick release system on these. On the right side is a disk with notches and a pressure pin that stops the notches. You tighten that disk to what you wish and then close the lever. If it's too tight the levers will have difficulty closing. It's easy to adjust, stays where you set it and allows you to adjust for the different rails in a minute or less. It also allows you to flip those quick release levers back or forward within minutes. For the Tavor or an AR I'd flip them forward again. The only flaw is you can't flip the quick release levers over to the right side. But at half the cost of the competition I'm willing to live with that.
Looks cool on the Tavor too
If you're planning on going holographic site with the RFB. I'd actually recommend the M21 bullseye sight with quick release from the Tavor. The levers are on the right side. the Eotech was too wide and interfered with charging handle operations. A Bushnell holo dot (same internals as eotech but no longer made) might also work. Or putting the Eotech really far forward might be an option. I prefer it back personally.
Eotech 553 (quick release) on the RFB. Not a good match. The base is too wide and you'll hit your hand when using the charging handle.
M21 quick release with bullseye reticle. Eotech like reticle and quick release levers on the right hand side. Plus it's not as wide as the Eotech. This combo actually works fairly well. Iike the M21 on my RFB, Tavor and CX4 storm. It suites them better than the Eotech. Although I do prefer the Eotech overall.