I've owned/own both the HD B' and EL Range along with the Zeiss combo unit and the Leica Geovids.
All four units have their advantages. For me the best rangefinding capablitlies actually goes to Zeiss. If they come with angle comp, I will dump the others for the Zeiss. I am that impressed with their unit. The Zeiss also functions better than the other two in sub zero temps and that is VERY important to me as I do a lot of sub zero coyote hunting.
With that said, they are all three great units with great glass. For me the glass edge goes to the Swaros. I had the most trouble with the Swaros in cold weather. The Leicas aren't much better.
The Leica HD B's definately have the most "bells and whistles" as far as ballistics go, but I don't really use any of those features. I do like the temp, humidity and angle readings the Leica's provide.
I currently own the Leica HD B, but if I had to chose ONE of the four right now, it would still be the Zeiss. If you have any specific questions, fire away. I've put all four of these units through the paces in all kinds of different conditions.
It is an absolute travesty that NONE of these units take care of archers with angle comp. capablities.