I love MonaLisa a lot. I’ve been using it for pretty much all monospace throughout my computer. It feels very fine-tuned and well thought out, and it’s very readable too.
My only complaint, based on the image you posted, is that I had to look at the len above the === to tell how many equal signs there were in that operator.
EDIT: After checking the website (and looking at the operator again), the font uses custom ligatures. However, the full version also costs $150.