This.I’ve used both 66 & 77, still own the 77. As others stated the eyepiece on 77 is definitely superior to 66. In dimmer light the 77 is much more useful to me. I only care to own one spotter. If I owned 2 I’d probably have a 55 & 88. The 77 hits a sweet spot for me. I’ve carried it around plenty
Wyo2 is right on the money. While the 66 with the 20-60x eyepiece is still pretty good optically, the FOV sucks. The 30x wide angle eyepiece turns it into a whole different scope. Better color, a larger apparent FOV than my ELs, razor sharp and there is hardly any edge distortion. For less than $1,000 used, it's the best i've put my hands on; and it's less than 3 lbs i think. But yes the 77 is a better scope overall.I have a 663. As others have stated, the 20-60 te-9z eyepiece hampers its performance. However, I picked up the te-14wd 30x eyepiece for a steal on ebay and it brought the 663 to life. It's so dang clear and with a wide field of view, a real pleasure to look through. The 9z eyepiece just doesnt do the scope any favors. The te-14wd is also considerably shorter in length which fits in a pack pocket easier. If I need to get a little closer view I just throw my camera up to it and zoom in.