I loved reading this.
This is my second VNA, my first being Damaged Goods, and I think I should've saved it for later. This seems like the conclusion to Chris's story and I definitely would've appreciated him more if I'd read stuff like Original Sin, So Vile a Sin, Bad Therapy, and I think Eternity Weeps. I got some deaths spoiled for me :( and there were also characters who were apparently friends with the Doctor but I didn't know anything about them and I think that also hindered my reading experience a little. The story overall doesn't require any prerequisites, it's just beneficial to be familiar with all the characters in this.
Chris still made a huge impression on me and he's already up there as one of my favorite companions. Damaged Goods didn't really do much with him but this book analyzes his character and gives him so much depth. The Doctor is also so interesting in this book. Things happen to him that are shocking and his characterization as the seventh doctor is perfect.