I just picked up the Sony a9 III and noticed it feels a bit small during long portrait sessions. I am looking for a solid vertical grip to improve the ergonomics and battery life. Has anyone tried third-party versions, or should I just stick with the official Sony VG-C5? Which grips offer the best build quality and button layout?
Just sharing my experience: I bought the Meike MK-A9III Pro Battery Grip for $80. It solved the size issue for cheap and I'm honestly satisfied with how it works. Peace!
For your situation, I'd suggest checking out the Vello BG-S8 Battery Grip for Sony a9 III as a cheaper alternative, usually around $90.
In my experience, you gotta just bite the bullet and go official. I tried a Neewer Vertical Grip for Sony a9 III and it was honestly a letdown. The build quality was kinda trash and it felt loose on the body.