I just happen to have in stock [this from December 2007] three of the best binoculars, a Zeiss 7X50B (porro prism), Zeiss 8X56 Classic (roof prism) and Swarovsky 7X50 (roof prism).  Ideally I should have military-version Fujinon and a Leica to complete the set...but I don't.

The weight and 'feel'

There isn't much difference in the weights.  The Zeiss 8X56 (known for being lightweight) weighs in at 1050g, the Zeiss 7X50 (chunky-looking) 1250g and the Swarovsky 7X50 1280g.  The nicest to hold as regards 'balance' is the Zeiss 7X50, and its heavy rubber-armoured finish gave a very 'rugged' feel, though I also like the non-slip not-quite-rubber-armoured finish of the Swarovsky.  

Field of view for spectacle-wearers

All three have adjustable eyecups for spectacle-wearers and all three work perfectly, no loss in field of view whilst wearing strong spectacles. The Swarovsky 7X50 is by far the most comfortable, it is like looking through a window, even before the binoculars are close to the eye, even my wife (not a binocular enthusiast) said, "I like those, keep them!"  [Because I'm a dealer, I buy to sell, I don't keep].

Ease of use

The two Zeiss have fold-down rubber eyecups over the eyelenses (these do take four or five seconds to fold down and the rubber will perish in time);  the Swarovsky has screw-down eyecups, easier and more reliable.

The Zeiss 7X50 has thick rubber tethered lens caps over the objective lenses which you have to fold inside out to stop falling  back over the lenses, unnecessarily fiddly but they will keep the lenses clean and dry even in the rain (though, personally, I don't like to get expensive binoculars wet). The Swarovsky 7X50 has hard plastic (tethered) lens caps that fall neatly out of the way when removed. The Zeiss 8X56 has no lens caps.

The focus mechanism on the Zeiss 7X50 is by turning each eyepiece, very simple;  the Zeiss 8X56 has a standard centre focus wheel with individual focus for the right eyepiece (most people are used to this system though it's not as simple as individual eyepiece focus); the Swarovsky 7X50 has a centre focus wheel and another wheel in the middle of the focus wheel to focus the right eyepiece - a bit fiddly but fine if you set them for your eyes and don't let anyone else adjust them.

Optical quality

The Zeiss 8X56, being more powerful than the other two, has a lesser field of view and noticeably (to my eye) not as bright. The two 7X50s are very close in quality, I had to study them quite hard to see a difference.  In the end I decided that that the Swarovsky 7X50 is slightly brighter and the Zeiss 7X50 was, possibly, slightly sharper. The two Zeiss showed very slight distortion around the very edges, just noticeable on the 7X50, very slight on the 8X56;  the Swarovsky 7X50 was about as close you will get to perfect.

Conclusion

I know the Zeiss 8X56 is one of the great classic binoculars of all time, and if you don't compare it with anything else you will be amazed at its quality...but when I compare it with the two 7X50s I prefer the 7X50s, the image is brighter, the field of view is wider, they are more comfortable to use, and think the Swarovsky is the better of the two by a small margin.