This last conclusion, “players should do exactly the same regardless of rules”, always holds except for when very specific events kick in. These are:
-
One has an option to create a Seki with either odd dame / different total of eyes of each color, or not to create it. This is extremely rare.
-
Superko rules (basically nobody uses this: Even at AGA major tournaments, which are supposed to use situational Superko, people have been seen replaying triple Ko games instead of using Superko, probably because they do not know the AGA Superko rule)
-
One side has a position where he does not need to defend, just because if the opponent plays, a Ko would arise and the player has more than enough Ko threats than the opponent (also rare, but Go Seigen was involved in a rule dispute twice because of this, and curiously, the authorities ruled against him both times, even though he faced different sides each time http://senseis.xmp.net/?RuleDisputesInvolvingGoSeigen).
-
Positions like bent for in the corner, together with unremovable Ko threats (seki), at the same time. Very rare.
Number 3) creates a one point different in the score for such a position, which is also very rare. The reason is that modern Japanese rules force the player to defend anyway (there are no Ko threats in hypothetical play), so he has to give up a point of territory. Under area (chinese) rules however, this defensive move can be made at the end, when all the dames have been filled, with no penalty at all. Note that dame points count as Ko threats for the purposes of such a Ko, since the player that wins the Ko is trying to win it without having to defend.