First, the official description from IDW:
The epic crossover between the two greatest science-fiction properties of all time ends here! Our heroes launch a desperate mission behind enemy lines in hopes of ending the CyberBorg threat, but there’s a traitor in their midst…
As the final issue, the cyber-controller also makes an appearance. If there’s one thing that’s instantly noticeable, its that the font and speech bubbles used to convey this character are difficult to read. This isn’t much of a problem, however, since the dialogue in this one scene isn’t that worthwhile. The Cybermen are meant to be emotionless, so the dialogue between the doctor and the controller feels somewhat forced, and unnatural for a Cyberman. If you know your Doctor Who, you might feel a bit let down by this portrayal.
Regarding the actual ending itself, I’m sure many will find it satisfying, but it will ultimately depend on what you expect. Neither franchise has a zealous preference for action, so the ending here is more subtle. That said, you still get a decent dose of action and excitement leading up to the final conclusion.
As an overall series, Star Trek/Doctor Who has certainly been entertaining, paying homage to both franchises and celebrating the key similarities (and a few of the differences). The ending certainly leaves a sequel possible. Although, given the nature of both Star Trek and Doctor Who, it isn’t something the writers should have felt the need to force.
That said, the final twists at the end offer a final treat for readers. It doesn’t feel that threatening and overwhelming – its the last issue, so you can figure out that things will get wrapped up quickly – but it gives you a little something extra when the CyberBorg is dealt with.