Most of the time with higher end makes and models of binoculars, the BaK-4 glass is the superior choice. BaK-4 helps to eliminate internal light scatter and the images seen through these binoculars are sharper.
Porro vs. roof prism. One isn't necessarily better than the other in this case. Porro type is in the traditional style of binoculars with offset prisms.
The Roof prism is found in the the compact type of binocular with the prisms inline with the lenses.
There are many, many more terms like these and I will explain and define them periodically.
Have a nice day!
