Don't have an a9 but one of the fave user
settings among Sony users is something
not available with SLR viewfinders:
MF Focus Magnifier.
No one can tell you where to assign your
activation of it. The a9 has more custom
buttons than other models, but put it onto
a really convenient button. MF Magnifier
is verrrrry habit forming. Using it with the
eye level finder ... not needing to switch
an SLR to its rear monitor LCD ... is one
of the great features of non-SLR designs.
Works great even in bright sunshine, also
allows chimping without looking foolish :-)
Also, if your vendor offers an expanded
warrantee and the window to opt in on it
has not yet closed, do get in on it. An a9
is a major item to just toss in the trash. A
typical expanded warrantee allows total
replacement and covers accidents. So if
you send your a9 to Sony Service for any
reason and it comes back allfuktup [as is
normal] you can just drive a truck over it
and the expanded warrantee replaces it !