Hello Mike,
to give you my 2 cents, I'd say that for me, body size is important, but up to a point. What is more important to me, however, is how comfortable I am while playing in first or second fret position .
In other words, I like my left elbow to be as close to my body as possible, because if I am playing a lot of stuff below the fifth fret ( and that's where many of us are likely to be most times), I do not want to have my arm sticking straight out , because after a while it feels like it's about to fall off. I personally would not like a 3/4 size standard for that reason. The straplock is too far from the 12th fret for me. Even the regular standard body is slightly uncomfortable for me for the same reason, since I like the bass to rest somewhat high on my body. A Fender Jazz or Precision has the strap-pin very close to the 12 fret, so those have always been comfortable instruments (in that respect at least).
However, I'm just under 5'10; one of my best friends who is 6'2 , and arms to match, has no problem with those same models, because of course he has more reach and he doesn't end up with his arm straight out like I do. He also likes to hang his bass lower than I do.
I guess I would sum up by saying this: consider your size as well as the size of the bass, and your playing style as well. If you're tall or if I you like to keep your bass at belt level, then my above mentioned problem would likely not be a factor for you.
My feeling is that when you purchase a work of art like an Alembic you want to make sure that it's as comfortable as possible for you.
Take care
Valentino