Gary, you make good points; Russian/Baltic/Artic birch is NOT guaranteed to have no voids and the only way to get this assurance is to go with marine plywood, but this is fairly big bucks.
Your comment on wood core plywood is timely as I did ask the yard in NH about the availability and here is what I was told, that it is, for all intent and purpose discontinued but that with a 100 sheet minimum it -may- be possible to get a custom run, imagine what the cost would be?, and while I am not certain, I do believe that the wood core was noted for some warping, but again it has been many many years since I have even seen the stuff.
Here is my report on Baltic birch: the 3/4 equivalent has 13 plies and I also ripped my 5x5 sheet; beware the dust BUT I am leaning towards what I was told that the dust is the wood, not the glue as the smell was a woody aroma not a chemical/formaldehyde smell, of course we all wear dust masks now anyway, right?
Not a single void to be seen and it machines very well, yes you have some sense that your router is shaping plywood rather than wood, but it is a gut reaction rather than one from the machine-not a single chip nor a single instance of 'spirited' router behavior.
For a little bit more cash you get about twice the plies, probably no voids and the flattest stuff you will see this side of mdf-I would be shocked if anyone is not happy with the product.
PLUS you will be hard pressed to see the difference between the Russian 'B' grade and ANY domestic -A- grade, seriously-apparently they have far higher standards in Europe than we have here with regard to face grades.
Double plus, you can leave the edge banding in the drawer, the finish on the edges of the Russian product is begging simply to be lightly stained then gloss sealed, very very attractive.