Not really. 5 ml of simple syrup is not the same as half of the amount of rich syrup. Simple is 50 Brix, rich is 66 Brix
Thank you for the reply/clarification. So, being approximately 1.3 times sweeter, rich syrup is more of adding texture (and slightly more sweetness) to a cocktail than anything else. Plus the advantage that it doesn't have to be refrigerated.