This is my first time using a CF Card. (It's very confusing)This is the TYPE B CF Card. Nikon z6ii uses it (and Nikon Z7ii also uses it)Reason to buy the 256GB Pro Grade card is that the speed is FASTER than the 128GB version.PLUS the Z6ii (and Z7ii) only has ONE CF card slot. So instead of buying two different smaller cards i just bought this one larger card.CF cards are supposed to be much more dependable and durable than SD cards. So i'm hoping this CF card last for years without any errors.Also, if you have the z7ii or a future 40+ megapixel camera. The 256GB will help with the larger files.So i think the 256GB is a good long term investment.BUT yes it's expensive. That's the only bad thing bad thing i have to say about it.I got mine on sale for $271 recently (not including tax).So if you're hoping to buy one, wait for November (black friday) the price may go down a bit more.____________________QUICK INFO:Nikon Z6ii with this 256GB card i can do:FX Mode: 5,000+ Raw PhotosDX Mode: 1,100+ Raw PhotosWhich means you can take a TON of photos plus do video on the same card.FX & DX mode (14bit mode) buffer: 34 RAW photos before buffer fills upFX & DX mode (12bit mode) buffer: 46 RAW photos before buffer fills up.________________________________________The buffer quickly recovers with this CF card. I never owned a top end sports camera like the D5, D6, etc.. But this shoots so ridiculously fast it feels like i own a D6 high end sports camera.(My previous camera was the Nikon D750)If you switch to jpeg, you could probably increase all of these numbers but i shoot RAW. No one should be buying this type of equipment to then shoot in jpeg. That would be a dumb waste of money. So i won't bother testing jpeg mode.I don't do much video right now but i also tested recording some 4K video and it worked fine. No issues to report.I also tested my SanDisk 95 MB/s SD card in the Nikon z6ii. It's TOO slow to handle the speed of the Nikon Z6ii. So don't cheap out. Get a good CF card. This one works perfect.HOWEVER, i didn't get to test a UHS-II SD Card. They sell 300 MB/s SD cards. That could be your 2nd best option but they are slower and the price isn't that different than the CF cards. That's why i bought this Pro Grade CF Card.AND YES CF cards can run a bit hot. That is normal. After i transferred files the CF card was a tiny bit warm but nothing serious.________________________________________MY SETUP + SPEED TEST:I did a real world test. (Long story short i got up to around 630ish MB/s in my test and setup)I tested this using the USB-C port on the back of my motherboard.And i tested using these 3 pieces of equipment:____________________1. USB C to USB C Cable,Rampow [100W,USB 3.2 Gen 2X2]https://www.amazon.com/gp/product/B0827CR8GWThis USB-C to USB-C is listed as:Max speed: 20GbpsIs that read or write or both speed? I don't know____________________2. ProGrade Digital Memory Card - CFexpress Type B (256GB Card)https://www.amazon.com/gp/product/B0863981FZThe 256GB card is listed as:Max Read: 1700MB/sMax Write: 1400MB/s____________________3. Dual-Slot CFexpress Type B and SD 4.0 UHS-II Card Reader USB 3.2 Gen 2 10Gbpshttps://www.amazon.com/gp/product/B08RF1QBTNThis card reader is listed as:"Transmission Speed": 10Gbps"Data Transfer Rate: 5000 Megabits Per Second, 10000 Megabits Per Second"____________________THE TEST:I transferred 214 Nikon Z6ii Raw files and a few short MP4 videos from the CF card directly to my PC's desktop (Which has a M.2 SSD gen 3 drive), via the card reader and using the USB-C to USB-C cable.____________________THE RESULTS:IT'S FAST!I saw transfer speed hit over 600+ MB/s.I think it went up to a MAX of around 630ish MB/s. But when i screen shot it the speed was jumping up and down from around 500ish MB/s to 630ish MB/s. Some where around there.So when i screen shot it, it was at 590Mbps.20Gbps? No where close BUT it was still REALLY fast.Before my Nikon Z6ii upgrade i was shooting with a Nikon D750 and a 95 MB/s speed SD card.The speed difference is HUGE.____________________NOTE:I do see on the card reader product page, someone screen shot a read and write speed of 900+ MB/s. So there's either an issue with the USB-C cable, the CF card or..... MAYBE it's just the USB-C port on my motherboard is not performing to it's MAX potential.Most likely an issue with my USB C port? (I don't know)____________________THE CONCLUSION:I doubt you'll get the MAX speed out of this equipment but it's still plenty fast. This is a huge upgrade for me doing photography vs when i was using a slow 95 MB/s SD cards with my Nikon D750 DSLR camera.Pro Grade sells their own card reader which cost more. There is a chance using the Pro Grade card reader you may see even more speed when transferring files. But if i can't get the MAX speed already i doubt the pro grade reader will work any better AND this card reader and setup is more than fast enough.So i'm very happy with this setup. I highly recommend it for photographers / videographers.The only bottle neck left is software. Adobe Lightroom can be ridiculously slow. It's now my last major bottle neck.