While Oberwerk's models may have a higher spec, better warranty and customer service, the LW design is still the same as the infamous Celestron Skymasters.
I have some Oberwerk LW 15x70's, and they are definitely much better than the Skymasters(the one's I've seen and Glenn's thorough description). Their coatings are on all air-to-glass surfaces, and quite effective. Also I measured mine at closer to 68mm effective aperture, but it could've been innacurate. The prisms mountings might be a bit delicate, but I have had mine tip from a tripod, and survive with collimation intact, so they have some basic ruggedness. They have a wide field and a good sized sweet spot. And the edge doesn't get annoying fuzzy. Also, the difference between 10x and 15x will allow you to resolve many open clusters from a fuzzy patch into stars. It really is a different sky at 15x. I've found that they work ok hand-held from a zero gravity chair for a while, but a parallelogram or tripod, or chair mount will allow much more resolution through steadiness.
They have a log eye relief and that does help with fogging. You can buy a lot of dessicant for the price difference to the Ultras. And you will see 98% of the same stars as the more expensive units, they just might have a slightly better view, and in a dark sky, you definitely see stars that aren't in an atlas.
For exclusively "hand held" astronomy, I think 8x56 are a great size, or even 9x63, but by 10x50 or 11x70, it will be very shakey, if not right away, after a few minutes. Even with steady hands, any bit they shake will be multiplied by the magnification, and it definitely make a visible different. 7x50's are very popular for this reason. Though you may not see as deeply, it will be a pleasant view.