The rumors of increased Dial-up lag in SFC3 with the Beta patch are, in my experience, greatly exaggerrated. You'll find very few problems with Nanner's Generations @ War mod, since he eliminated shuttles, which appear to be a prime cause of lag across the board. I hosted 3 or 4 players, most with broadband, on a Planetary Assault mission and had very little lag reported. The other things that seem to cause the lion's share of lag in SFC3 are models with polygan counts over 5000, certain weapons textures and sounds, and impact of weapons fire on an unshielded hull. All but the last can be reduced by making a few substitutions to your game files, and I wouldn't doubt that impact lag goes down with higher amounts of RAM, and/or faster processors, so the damage can be calculated faster.