I enjoy 8x20 bins more than most, but I agree with the cautions about replacing full-sized bins if you enjoy the latter regularly for dedicated birding or when you aren't traveling. I think the biggest issue for 8x20 roofs is handing, closely followed by optical quality. Good handling helps mitigate optical issues and the inherent need to hold these bins precisely to get the best optical performance. For those reasons, the Leica 8x20 Ultravid is by far my favorite, and I like the BL version best for being maximally compact. The Ultravid can be held and focused etc in very similar fashion to full-sized bins, making it much easier to use in critical/difficult situations than most pocket models (see this post for photos and handling tips
http://www.birdforum.net/showthread.php?p=2805064&highlight=imbedded+grip#post2805064 ). I like the focus on the Ultravid better than the Zeiss 8x20 Victory, but otherwise, I like the Zeiss Victory just as much for other handling characteristics and optical quality.
In my opinion, the Zeiss 8x20 Conquest (which I have tried on numerous occasions) is a piece of junk, or perhaps it is more fair to say that it feels like flimsy glued-together cheap plastic, I wouldn't pay Zeiss prices for its level of build and optical quality, and it is at the poor end of the spectrum when it comes to handling. In comparison to the Ultravid or the Victory, the optics are not as good (contrast, edge correction), eye relief though specced similarly is not as good, the fold down eyecups are awkward to use, the hinges are fiddly because they lack positive stops (not a fair trade in my opinion for very slightly smaller folded size compared to Ultravid), hinge tension is usually low so it doesn't hold IPD setting well, doesn't allow easy wrap-around grip because of hinge design, focus position and operation is awkward, close focus is much inferior, not designed to take a proper neck strap, and doesn't "hang" properly.
I totally know what you mean about juggling camera, water bottle, guide book, and bins while walking around archeological sites. The primary draw is the location and the ruins, but it's nice to get good looks at the resident birds, lizards, and insects as well. For me, the 8x20 Ultravid, kept at the ready, unfolded to my proper IPD on a light neck strap is the perfect solution. It is light weight, hangs flat and out of the way, and so is easy to forget until I need it. Most of my travel shirts have big front pockets, so when I want it to be a bit more restrained, or protected (when leaning over to look at things on the ground, or to keep drips of sweat or bits of my lunch off the oculars), I can usually leave the strap around my neck but drop the (still unfolded) bins into a front pocket with a single button or Velcro closure to keep it in there, yet easy to quickly access.
--AP