Well...I like my binoculars too, but I don't usually use them for birding. I'm an astronomy nut (I've built about ten telescopes) and so my usage is going to be different than yours. I don't believe in taking expensive or heavy binoculars backpacking. I have a pair of cheapies (Tasco 10x30) that I bought for under $15 at Big 5 one day. I bet I tried about six pairs before I found one that had reasonable focus and resolution near the edge of the field. And they only weight about 9 ounces.

Both of the pairs you suggest are quality optics...I'd go for the larger objective lenses, just because they gather more light...