>>2525329Reliability, as in the amount of use, banging around. etc they'll withstand before something breaks like the lens seals.
Resolution is a big one. Better bins are better able to resolve small objects. Matters if you are trying to count points on a durr, for example.
Color is more true on better bins, important for bird people.
Generally the mechanics are just nicer. The focus knob stays where you put it, as does the ocular adjustment.
You gotta use the things quite a bit to wring out the differences and that gets more true the more expensive the bins. I've had Swaro ELs and they are great, but I didn't really use them enough to justify the price difference between them and my trusty Zen Ray ED3s. Sold the ELs, they hold their value really well another good point for top end ones.
