This is how we do peer and manager feedback at Medium.
As a reviewer, it is still challenging, but less so than open ended text areas. The structure provides more guidance and gives you an easy out: sometimes a blank can be as simple as a noun phrase, or it can be multiple sentences.
For the reviewee the synthesized, aggregated result somehow feels — perhaps unintuitively — less sanitized and more honest. It's nuanced and actionable. You can look at it and ask "how do I want to be seen next time?"