I personally enjoyed Once Upon Stilettos quite a bit because it is such an original plot and overly quite enjoyable. The characters are real, the danger feels malicious, and the ending is to die for.
The one part that I enjoyed the most was definitely the romance: I am a true romantic and will never change. Here, it was a budding relationship, unknown on both parts, and left me breathless. The plot was tangible and interesting, and the magical talk was most definitely delicious.
I am definitely looking forward to the next book :)