I've read some disparaging of the Immelman module but I quite like it when coupled with a Fulgora and blink. Won a lot of dogfights with it. Reverse direction, blink past the foe chasing you, and then the Fulgoras 360 azimuth cannons can wreak their havoc. By the time they turn around the blink is recharged.
So few people use it that it usually takes a foe by surprise, too. Biggest advantage it has over boosting speed and turning horizontally is that you can blink mid-Immelman. Lets you change altitude instantly. What I'd like to see changed is the animation. The Immelman turn is so segmented and stiff it seems like a placeholder animation.
If it was sped up, that might also make it a more versatile module instead of a niche dogfighting module. What's the community opinion?