For your situation, I've tried a few different setups over the years because I totally get not wanting to drop tons of cash on official gear... anyway, in my experience, while the Canon BG-E21 Battery Grip is built like a tank, third-party ones are actually pretty solid for the price. So basically, here is the breakdown:
- The Vello BG-C15 Battery Grip for Canon EOS 6D Mark II is probably ur best bet. It feels more premium than the super cheap brands and the shutter responsiveness is lowkey great.
- The Neewer Vertical Battery Grip for Canon EOS 6D Mark II is the budget king, though the plastic feels a bit thinner and the dials can be kinda stiff sometimes. I'd go with the Vello honestly. It handles two Canon LP-E6NH Lithium-Ion Battery packs perfectly and the ergonomics are a lifesaver for portraits... ur wrist will thank you later! Good luck 👍

yo, been thinking about your question. honestly, i went through this last year trying to save cash for glass. just sharing my experience: i picked up a Meike MK-6DII Professional Battery Grip for like $55 cuz the official Canon one is basically highway robbery. unfortunately, the shutter button felt kinda mushy and i had some MAJOR issues with it draining my Canon LP-E6N Lithium-Ion Batteries even when the camera was off. super disappointing when you've got a long shoot and your gear is suddenly dead... basically, i learned the hard way that while these budget options look good, the electronics can be sketchy. i mean, others mentioned they're okay for hobbyists, but idk if i'd trust that unit for a serious portrait session again after my experience with that shutter lag. definitely be cautious... TL;DR: Tried a $55 Meike MK-6DII Professional Battery Grip but the lag and battery drain were honestly a nightmare for my workflow.

Tbh I totally agree with that point about the technical quirks and electronics - I’ve spent way too much time researching the market for these things and it’s basically a 'you get what you pay for' situation every single time especially with the 6D2. From a market research perspective there are really only two other players worth mentioning if u want to avoid the issues mentioned earlier: - Pixel E21 Vertical Battery Grip: This is probably the best middle-ground option because the rubber grip texture actually matches the camera body reallyyy well and it doesn't feel as hollow as the super cheap ones - though the shutter button has a slightly different travel distance than the native one which takes some getting used to.
- Vivitar Multi-Power Battery Grip for Canon EOS 6D Mark II: This is the bargain bin choice - it’s okay for ergonomics but the dials feel super light and clicky and I’ve heard reports of the tripod mount threading being a bit weak if ur using a heavy lens for portraits. TL;DR: If ur doing paid work just bite the bullet and get the official Canon BG-E21 Battery Grip for peace of mind but if ur just looking for better ergonomics on a budget the Pixel model is basically the most reliable alternative I've seen.

@Reply #4 - good point! ngl this thread brings back memories of when my cousin and i both bought grips for a trip to the rockies. he went with some budget brand he found on a clearance site and i had my older reliable setup. halfway through a hike in some light mist his camera just started acting possessed... like the shutter was firing on its own and the menu kept cycling through settings. we compared the two side-by-side and you could literally see where the weather sealing on his was just... missing. it was basically just two pieces of plastic snapped together with zero protection for the electronics. he ended up having to bag his whole rig for the rest of the trip while i was still shooting. it was such a weird ordeal because on paper the specs looked identical but the actual real-world performance was worlds apart... definitely made for some tense car rides back to the hotel lol.

Before I give advice, I have a quick question: are you shooting your portraits mostly in a studio or are you taking the camera out into the field? I ask because while those brands mentioned earlier are usually fine for hobbyists, you really gotta watch out for some technical quirks that come with going third-party on a body like the 6D2. Basically, keep these warnings in mind:
- Weather sealing: Unlike the official ones, the cheap ones usually don't have gaskets, so moisture is a huge risk if it starts drizzling.
- Battery communication: I've seen them fail to read the chip correctly, meaning you won't actually know when you're about to run out of juice.
- Button lag: Shutter responsiveness can be hit-or-miss depending on the batch you get. It honestly depends on your typical shoot length too... if you're out all day, those little electronic glitches get real annoying real fast. Let me know about your environment and I'll give you my take!