Honestly speaking, I think the rates are better than many games out there. The chance of drawing a 5* potential is around 5% whilst the chance of drawing a Rate Up Hero is around 1.7%. Besides, if you really want a specific Hero so badly, you can always use Valianite.what i can conclude from ur video, only... even they say rate up, but the rate still suck:\
Yup it's around there.The summon rate is always rock bottom. If rate up is aggregated at 1% then without rate up is 0.5%.
Statistically, on rate up duration, you need to summon 100 units to get 1 rate up unit so that will be 4k gems.
Without rate up, well, good luck. In this way, valianite is your best friend.