I was able to borrow a set of the Zeiss Victory RF a few days ago, so I've been able to do some head to head comparisons of these 3 over the last couple of days. What follows is a very unscientific summary of whatmy 44 year old eyes could see. I also didn't have these on a tripod, which would have helped a ton, so buyer beware. Your mileage may vary.
I set up a few resolution charts about 50 yards away from my front porch. During the minutes of low light right i dusk, I did a whole lot of comparison between these three.
My first overwhelming conclusion: there's not much difference between these 3 optically. I had convinced myself that the swaro El Range was outdated and not as great as some others. While i do notice a difference between the el Range and the EL Swarovision binos, it was really really hard to pick out much difference between the Swaros and the Leica and Zeiss. There are small differences in the sweet spot and the edge clarity and the cast of the hues, but it is so stinking small.
The only real difference i saw was literally in the last 2 or 3 minutes of visible light. The Zeiss and Leica were able to resolve just a hair longer than the swaros. And really - i had to try really hard to see any differences between any of them optically.
If you're on the fence and want to upgrade simply due to optics, I'd hold off. It's not worth it. If you want the ballistic stuff in the zeiss and leica, then it's probably worth it.
Anyway, a few of the other differences. The ergonomics are quite different between the 3. The swaros were like an old friend since I've used them for so many hundreds of hours, so i can't be unbiased. They felt the most comfortable to me because they were the most familiar.
Between the other 2, the Zeiss, for me, was considerably more comfortable to hold. The focus on the zeiss was better than the leica - more precise and smooth. The leica will probably break in with use, but as is now, it was stiffer and trickier to find that perfect spot. It was "spongy". The Zeiss could dial it right in.
Button placement - it is perfect on the Leica. Easy index finger push. On the zeiss, it will take some getting used to. It's further down where the ring finger sits, so to zap something, you'd have to get used to gripping them further down the barrel or hitting it with a different finger.
My honest opinion is that i wish swaro would come out with their version soon, because i'd own it for sure. In the meantime, I'll be running the Zeiss. Because they are more expensive, i'll look for a used set or a demo or something and try to get a good deal, then likely sell them when swaro comes out with theirs, for no other reason than i love swaro as a company, the rest of my stuff is swaro, and they've treated me like gold over the years.
Zeiss's phone app is also light years better than Leica's. I'm sure Leica's will catch up, but Zeiss has them beat right now. The Zeiss app has a lot of fluff that nobody will ever use, but the base ranging stuff and bino syncing stuff is easy and straight forward. I continue to have issues with the Leica functionality. I think i got a defective unit.
If anybody has questions, let me know and i'd be happy to help.