I love a good M/M read, and I had high hopes for Double Full, but in the end it fell flat. I enjoyed the MC's, but their relationship seemed forced in my opinion. I was expecting conflict for these character's, and the conflict was there, but all the issues that they had going on were resolved fairly quickly.
The pov of a third character showed up unexpectedly 3/4's of the way into the book. The unexpected pov was a thrown in as a set up for the next book in what will be a series apparently. The addition is something that annoys me; especially when it's done to draw the story out for future books.
The story ended with a HFN, but it's open to interpretation due to a mystery being left unsolved. Editing issues were also noted.