SRB % rewards

Hi guys, I would like to discuss about super rebirth, and about the % money and xp that you get from it, I would like to know what is better and why, to super rebirth fast at rebirth 20 again and again, or to super rebirth around 35 but it takes more time, how much more worth is the higher percentage xp and money you get. Because I saw a guy that rebirthed like 750 times, and I super rebirthed like 9 times at rebirth 35 and I’m a much higher level than him also my other upgrades are way better, if someone could explain it better to me, I would appreciate that! Thank you