Sooo first off, congrats on the R6!! Honestly, it's literally such a huge leap from a DSLR, but yeah, the battery life is definitely the first thing you'll notice. Basically, mirrorless cameras eat power way faster cuz the electronic viewfinder and screen are always running. In my experience, you don't actually have to drop $80 each on the official Canon LP-E6NH Lithium-Ion Battery if you're trying to save some cash. I picked up the BM Premium 2-Pack LP-E6NH Batteries and Dual Charger for like $40 on Amazon and they've been pretty solid! I mean, you might lose a tiny bit of that max burst speed when they're not full, but for a day of shooting, it's a total lifesaver for the price. For cards, those V90 ones are sooo expensive. If you aren't doing heavy professional video, I'd suggest the Lexar Professional 1667x 128GB SDXC UHS-II Card. It's a V60 card that costs around $45, which is way cheaper than the V90s but still fast enough for 4K and those quick bursts. And definitely don't pay full price for the Canon adapter if you're on a budget! The Meike MK-EFTR-A EF to EOS R Mount Adapter is usually around $50 and works just as well as the brand name one for my old lenses. Idk, it's just a metal tube with pins, right?? Anyway, hope that helps ur wallet a bit - enjoy the new rig! 👍

Check out 'Cameramemoryspeed' for technical benchmarks... im super satisfied with the SanDisk 128GB Extreme PRO SDXC UHS-II V90 for 4K, it basically works well, does that help??

just found this thread and honestly, i spent way too much time testing write speeds and voltage curves when i first got my r6. coming from a dslr, you dont always realize how much data these mirrorless bodies push thru the bus. i found that some generic v60 cards would actually stutter during high-bitrate 4k60, so i switched to the ProGrade Digital SDXC UHS-II V90 128GB and havent looked back. the sustained write speeds are just way more reliable for bursts too. also, since you mentioned the adapter, definitely try to get the Canon Control Ring Mount Adapter EF-EOS R. being able to add that physical control ring to my old ef glass basically made them feel like native rf lenses... i mapped mine to exposure compensation and it changed my whole workflow. one diy tip if youre worried about durability: get a screen protector like the ULBTER R6 Tempered Glass Screen Protector right away. since you use the touch screen for basically everything on the r6, it gets greasy and scratched way faster than an old dslr screen would. its a cheap way to keep the resale value high too.

Honestly, when I made the jump, I spent way too much time looking at the technical white papers for the RF mount's communication protocols. The transition from the old DSLR tech is basically about managing data throughput and voltage stability across the system. - Tbh, I found that the market for adapters is split between those that just pass through the electronic signal and those that actually try to match the OEM weather-sealing and flange distance tolerances. I went with a version that had the integrated control ring, and the haptics were surprisingly consistent with the native glass. - Regarding the storage, I did a lot of benchmarking on buffer clearing speeds. While the labels say one thing, the actual sustained write speeds during high-speed bursts vary wildly between brands even if they share the same V-rating. The one I got handles the 20fps electronic shutter much better than my older UHS-I stuff.
- Also, look into PD (Power Delivery) standards if you want to charge via USB-C. The R6 is pretty picky about the wattage/amperage required to actually top off the cell while the camera is off. It's definitely a learning curve moving to a mirrorless architecture where everything is digitized. Just makes you realize how much more the body relies on the accessories to maintain that peak performance. Idk, it's a fun rabbit hole to go down once you start looking at the data.

Yep, this is the way

Just wanted to say thanks for everyone chiming in. Super helpful discussion.

For your situation, i'd definitely grab at least two extra batteries. i'm kinda cautious so i'd say just stick with Canon ones... i've had third-party stuff glitch out on me before lol. for cards, just get any high-speed ones from SanDisk, you can't go wrong. and definitely get that adapter! just be careful with the weight balance tho. gl!!