I would think that a smaller map size would less of a strain on database operations in general whether it's flatfile or SQL. I would also think that a smaller map would be easier to create in the first instance and easier to do db edits on if necessary or desired.
I'm not so sure about that anymore since we've found how stably the server runs with a static econ.
Right. How many hexes with how much econ each is needed for static econ? My hope is that you can tuck some hexes away off in the corner off maps or deep in the empire's space, but if it a tradeoff between map size and stability, stability would certainly be more important.
I have a thought, which may go along with all this, and not to similar to what the last map was, sizewise. How about a NO-FLY-ZONE for each race, all to be on an outside border. Have a second area for each race where you do your supplies, and is your homeworld etc... The outermost reaches could be separated by even a single line of neutral hexes that are designated as "outofbounds". NO ONE would be allowed to fly in those areas at all(not sure this can be done with the server, but a ruling in the rules pages that no one reads would help).
This way the "play area" is smaller, yet the econ can be more stable by having a larger map.