Update: I've been using the Endeavor and Terra for the past two days in my backyard. Interestingly, I thought the Endeavor was the clear winner (brighter and sharper) during the first day of use. The Terra was very close in terms of sharpness, but it just didn't seem as bright to my eyes. The sweet spot seemed about the same size on both binoculars. Color was also very close between the two, images were vivid and had good contrast.
On to handling: The focus knob on the Terra is very fast--I'm not sure if that's the right term, but minute movements of the knob seem to change the focus substantially. I prefer the knob of the Endeavor, which feels like it gives me more precise control. The knob has much more tension on the Endeavor, so perhaps that's what I'm feeling--it feels slower. The Endeavor is noticeably heavier than the Terra. The Endeavor is slightly longer and it does start to feel front heavy in comparison to the Terra, especially after prolonged use. The open bridge of the Endeavor helps to get a good grip, but that didn't make it feel any lighter. I really like the size and weight of the Terra in comparison to the Endeavor. It seemed like a small difference when I first started using them, but over the course of a a couple days I really stared to favor the Terra.
Conclusion?: After that first day I thought for sure I would keep the Endeavor. They are cheaper and, to my eyes, seemed optically superior. They weren't as comfortable for me to use, but they weren't uncomfortable. But the next day was overcast, so I thought I'd use them both again. Interestingly, the Endeavor and Terra seemed to be about the same in terms of brightness when the skies were overcast. Then, when looking at birds against a bright overcast sky, the Endeavor seemed more washed out and less sharp than the Terra. Colors were more saturated and there was better contrast with the Terra.
So, after a couple of days it seems that on bright, clear days the Endeavor was performed better. While on overcast days the Terra performed better. I really could go either way and I'm leaning toward keeping the Terra because they were very close to the Endeavor on sunny days, whereas the Endeavor was not as close to the Terra on the overcast day. My girlfriend, who was also tested out both binoculars seemed to notice more of a drop-off in performance with the Endeavor with overcast skies, though she preferred its handling to the Terra and thought it was much better than the Terra on the clear day. I think the solution might be to keep both. One for me and one for my girlfriend. Will update again.
