I gather that this isn't one of the well-liked Big Finish stories. I can't understand why people hate it so. The Roof of the World isn't as gripping as Chimes of Midnight(for example), but it's hardly at the bottom of the list.
I continue to enjoy the 5,Erimem and Peri TEAM TARDIS. I appreciate the way Big Finish builds up their original characters without slighting old favorites. The background we learn about Erimem is intriguing, and the friendship between she and Peri continues to shine.
For these reasons, I give The Roof of the World a solid three stars.