PJ has advised a number of times that the exact value is within a wide range for different iron. The MQ upgrade probably wants to have higher values. Like my Paramour, when I upgraded to MQ iron I went from 3.3uF to 10uF. By the way, I have an Obbligato there.
The range for stock iron, like you have will most likely include the 2.2uF that I suggest. Obbligato does not make a smaller value now. They used to, but don't now.
The difference you hear with changing values is mostly, but not completely, in bass extension. You might get 2 or 3 notes lower with larger values than with smaller. Not that most of us would really notice. I don't think I would.
The MQ iron upgrade is not cheap, but it was worth it to me.