Factors for me would be;
Vacancy, how many vacant lots do you have, how many vacant spots do the other parks have and are the other parks offering free move in specials.
Where is your rent compared to the other parks, if you are all the same but you have a cleaner park or better location, you're probably fine.
Demand, most things come down to the demand you have in your market. If it turns out to be a mistake can you fill the lots again.
I have a park in my area that is run by Frank and Dave that has higher lot rents plus sub metered utilities but it's a nice park with paved roads, club house and larger lots. There is value there.
Overall, if your residents are currently happy then it shouldn't be an issue. It does promote more responsible water usage.