The most valuable response to that question will be from
someone who has bought, used, and lived with b/hs from
both companies. Since there are few people on TBN who
have had both the BX80 and the JD 48, for example, you
are left with testimonials and specs, but few first-hand
comparisons.
On specs, you should realize that things like digging forces
are figured for different conditions, like test pressure. Weights
are given with bkts and without. More important would be
cyl sizes and apparent construction stoutness. 2 vs 1 swing
cyl is a big deal, too. Pin sizes over 1" are nice. Availability
of good subframes for your tractor is a must, unless you
build it yourself.
My 2c. (First hand experience with only one brand.)