I ordered one Racerstar RS30A BLHeli_S ESC, because I wanted to compare it with the Cicada 30A, that I received from Sunrise Model. Here is the result: both Racerstar RS30A and Cicada 30A are identical. They look the same, except for the different sticker, weigh the same and all electronic components are absolutely the same. If you need more information about the Racerstar, just check the review of the Cicada 30A. The only difference is the price: the Racerstar BLHeli_S is significantly cheaper than the Cicada. I got mine from Banggood for about 11$.
thanks!