A couple of months ago I launched an offering using ConvertKit Commerce and it worked very well except for two things. My offering is not a digital product but a workshop and I wanted to have limited attendees. I had to be checking all the time to make sure I didn't go over the number of seats. I had to move to Big Cartel and opt to pay their monthly fee because with CK:
1. We don't get an email notifying us of a sale
2. You can't manage the number of products available.
It's sad because I really loved the experience of setting up the product and the sale was super smooth plus no fee! But, I rather pay the fee than be stressed about having to tell someone.. have your money back.