What I liked: 
 1. a geeky and proud heroine! 
 2. A guy who wasn't as geeky but liked and understood her passion for it. 
 3. He's heavy into BDSM and she's vanilla - but I loved how they discussed it openly from the start! That was really my favorite part of the book - how they negotiated the sex in their relationship. 
 What I didn't like: nothing was awful. It moved fast, but I expect that in a novella. There was a little bit "just talk about it!" frustration, but it worked for me. 
 This is the 3rd in the series, but the first one I've read. It stood on its own just fine.