I use the service just after posting my article, to avoid forgetting.
The 24-hour rule seems perfectly normal to me, given the way HIVE works.
As far as limitations are concerned, I think you need to evaluate them over time, according to the amount of mana you spend.
!BBH
!ALIVE
RE: Small Update to the CryptoCompany Voting Service | Valid Only for Posts Not Older Than 24 Hours