I got properly rolled for NL20 (20 buy-ins).
It's like this : The tables at NL10 are very good, at NL20 there is very few tables and they are very tight. At NL30 there are many tables again and very loose.
To the main question is. Should I grind NL10 or take shot at NL30? Or maybe play NL20 even though they are tight?