1.5 is ok.
What is bad is that the best way to safrice is so time consuming. Eat a C1 with a C1, it'll became a C6, eat that C6 with a C1, it will became a C10, eat that C10 with a C1, it will became a C12.. keep going until its a C20. You will spend 8-9 Cs and 2025SP.
Now If you eat 8 Cs with a C1 it will be like lvl 12, and you would need a lot more to max it. Like 17 Cs and 4500 SP.
Why can't you just make that when you eat 9 Cs with a C1 it's maxxed????
It's just a stupid time consuming thing.