Even tho the size and weight are not that much different, the 65 is just so much handier and easier to transport. And optically, you don't give up that much difference. Especially in low light. Only about 2-3 minutes at sundown. And it is easier on a tripod or window mount. My 80 hasn't left the house during hunting season, except when I leave it in the truck on a window mount, for maybe 6 years. I used it exclusively for a few years before I got the 65. I reckon your experience wouldn't be different if you had both...