The route had some major changes between Diamond and Pearl and Platinum. In Platinum the second entrance into the Resort Area was removed (most likely due to the changes there). Also, the sea that connected to Route 230 is now gone, having been replaced with land, and the entire sea being solely on Route 230.
Trainers with a Vs. Seeker by their names, when alerted for a rematch using the item, may use higher-level Pokémon.
The two Ace Trainers that appear on the southernmost part of this route have their parties based on those of Butler and Diane in Jirachi: Wish Maker. In the Japanese version, as well, they are named as Butler and Diane, but the English translation team did not notice the relation to the movie characters.