Re: Binocular recomendations, PLEASE!
I'm not an optics expert.
Possibly the main difference you would notice between poro and roof prism is the price, and you could probably get better quality, dollar for dollar, in a poro prism.
Most variable binoculars are cheap binoculars. You need a mechancal connection linking the two sides and that means they are difficult to seal from moisture and dust; among other things. The makers of quality binoculars usually stick to fixed power to preserve internal integrity.
If you will not be lugging this glass over hill and yon, I see nothing wrong with a standard pair of competitively priced 7X50s. That's what I use. I think most people can define as much detail at 600 yards with a good pair of 7X50 poro prisms over an inferior pair of 10X50 roof prisms, for the same price.
For a walking around pair, I like 9X35s.
Good luck, LB