I grilled both burgers. First off, New Zealand lamb burgers. I have to tell you in all my years of grilling, lamb burgers are the WORST smelling meat I've ever grilled. They smell like sweaty feet and ass from a gym locker. Juices and BLOOD drips everywhere as it sizzles and ignites flames throughout the whole process. When I placed the patties on the buns blood still streamed all over the plate like a stuck pig even though the patty was cooked all the way through. The taste was fairly bland. Regular beef is better than this. Now, I have to tell you that the box recommended the lamb patties be seasoned with salt. But I don't believe in seasoning meat. So, the final word: Lamb burgers are a no-go.
Bison burgers, on the other hand, are the best tasting burgers I've ever grilled--period. Better than beef burgers, better than fully seasoned beef burgers. Better than even, dare I say it, Boca Burgers. There is no aroma while grilling but and very little blood. But juices flow from the patties like water from a babbling brook. For this reason I decided to get them off the grill as soon as possible--About 8 to 10 minutes both sides. The Bison patties for the most part maintained their integrity throughout grilling and during construction. The taste, though, is out of this damn world. The cleanest, softest, grease free meat I've ever had. Final word: Lamb burgers forever more.
NOTE: Burger images used above were borrowed from the internet and not actual images of my burgers. Nevertheless, my burgers were comparably dressed with the standard lettuce, tomatoes, and vidalia onion rings on a sesame seed bun. No cheese on either.