Overall, the anime based on Air Gear manga has its moments. It keeps the main plot intact but makes some changes to fit the animation format. Some fans like it, while others have mixed feelings.
Not much is known yet. Maybe there are new plot developments or character introductions. You'll have to check the latest chapters to find out for sure.
The release date of the Gear 5 manga can vary depending on the region and publisher. Usually, you can find this information on manga-related websites or forums dedicated to such updates.
Luffy uses Gear 5 in a significant battle towards the later part of the manga. But the exact chapter or arc can vary depending on how you're reading it.
To be honest, I don't have the specific chapter number for Gear 5. But you could check with fellow manga enthusiasts or look through official manga guides.