Yo, stumbled upon this and I totally feel u... clearing that R6II buffer is a total nightmare on slow cards. > I’m currently torn between getting a few mid-range V60 cards like the Lexar Professional series or splurging on the Sony Tough V90 Before I give advice, quick question: are you shooting full RAW + JPEG or just CRAW? It basically changes everything for those 40fps birding bursts. Honestly, I had issues with the Lexar Professional 1667x 128GB SDXC UHS-II V60—it was not as good as expected and felt kinda sluggish during sports... super disappointing tbh. If you're worried about cost, the ProGrade Digital SDXC UHS-II V60 Gold 128GB is a solid value pick. But for your main slot, maybe grab one Sony TOUGH-G series SDXC UHS-II V90 128GB? It's pricey but literally never fails. Anyway, let me know about your file types! gl

Tbh, if you're worried about reliability, you've gotta look beyond just the sticker speed and check the sustained performance. For birding with the R6II, you’re hitting that buffer hard and cheap cards will throttle fast. > Reliability is also a major concern for me since I've had cards fail in the past. If you want actual peace of mind, I’d suggest looking at ProGrade Digital SDXC UHS-II V90 Cobalt or the Kingston Canvas React Plus V90. The Cobalt series is basically designed for pros who can't afford a failure—they use pSLC (pseudo Single Level Cell) flash which has much higher endurance and keeps the write speed consistent even as the card fills up. Most mid-range V60 cards use cheaper TLC flash that tends to tank once the internal cache is exhausted. Like, it's not just about the 40fps burst; it's about making sure that data actually lands on the NAND without corruption during those high-heat sequences. Kingston is also surprisingly solid and usually way more budget-friendly than the Sony Toughs while offering similar V90 specs. I’ve run them in dual-slot recording for years without a single dropped frame or 'Card Error' message.

Honestly, everyone jumps to the big names, but ur often just paying a huge premium for the marketing. If you want a solid market alternative for that R6II, definitely check out the Angelbird AV Pro SD MK2 V90. They’re huge in the cinema world for a reason—the sustained write speeds are basically unbeatable for the price point. Another sleeper hit is the Sabrent Rocket V90 SD UHS-II. It’s usually way cheaper than the "tough" branded stuff but performs just as well in my experience for sports. Yeah, SanDisk is the classic choice, but tbh they’ve been coasting lately while these newer storage-focused brands are really pushing the value. Just stick to V90s for those 40fps bursts; even the best V60 will eventually choke if you're holding down the shutter for birds in flight.

Facts.

Totally agree that those 40fps bursts are *brutal* on the buffer. I'm still learning the ropes with my R6II, but I've been trying some DIY maintenance to avoid needing professional recovery services if things go south. * I always run a disk utility check on my PC every few weeks to catch errors early before a big shoot.
* Does anyone know if formatting via a computer is actually better for 'self-service' than just doing it in-camera? I want to make sure I'm doing everything right to keep the speeds stable so I dont miss any shots.