Well, I guess I asked for it in making my original comment:
1)Planet size re tech rsearch - multipliers:
Tiny Planet: 0.6
Small Planet: 0.8
Standard: 1.0
Large: 1.1
Huge: 1.6
And sure, on a huge planet there are more unused tiles to convert with solars and echelons to produce energy in abundance - but that's usually after 2250 or so, and most PBEMs don't last that long.
In the meantime, a base is still just utilizing its 20 tiles (excluding the homebase tile) whether on a tiny map or a huge one (until the advent of IA, which will come 20 years earlier under a tiny planet compared to a large or 40 if huge)
Unless in easy single-play mode you'll never hope to replicate the tiny planet's rate of research with anything larger - in multiplayer you'll never have the luxury of developing that energy park.
2) - early butt-kicking
Don't know about you guys, but I would sure hate to invest a month's PBEM time only to get ousted after 20 turns by a Spartan missile synthmetal rover rush - and unless you've scenario built it, when one goes the game crashes (unless the defeated player wants to continue for 100 turns as a slave - or gives his password to the conqueror - not much fun either way.)
Having said that (and my original premise was that nobody asked my opinion anyway) - I'll volunteer to CMN your game and build you a starting, balanced, tiny planet scenario when you have the players lined up so that you won't have a player disappearing after 20 turns
'Nuff said
Googlie (poking his nose in others' business)