Wow... 400k shots is a lot. I hope it will do the job for you for some time...
Yes it is. However I convinced myself when I looked at Oleg Kikin's Camera Shutter Life Database: from here
https://olegkikin.com/shutterlife/canon_eos5dmkiii.htm you see that 400k is equivalent to a ~78% survival rate, which is not too bad. After all I have 70k shots on my 70D and apparently this is equivalent to a 62% survival rate (cfr
https://olegkikin.com/shutterlife/canon_eos70d.htm), that is even lower! So I told myself, 1. If I keep using 70D for photo and use 5D3 for video, I should be fine; and 2. even If I had to replace the shutter on the 5D3 I would spend 200/300 bucks more, and this would give me a total of 500/600 € for a 'brand new' 5D3... which is not bad, considering that I see used models (with smaller -- but not zero -- shutter counts) being sold for 800 €.
Anyway, back to the main topic.
[...] I have 2 CF cards. And if one is full I use the other. And while this, I copy the data from card one to my NEXTODI.
Ahhh I see, so this is what does the trick. I had to google for NEXTODI

but now I realize. So I guess I will stick to a new 64 GB CF card for now (found an Amazon Warehouse deal for a Lexar 1066x @60€, seems a fair price to me as its €/GB ratio is equal to the brand new 256GB version). Hope 64 GB + 128 GB will give take me to ~30 min rec time, though I will have to do some file transfer from CF to SD from time to time.
If you just wish to record 1080p, the SanDisk SD card alone in the cam is good enough.
Yup, well, if I wanted to record 1080p I could stick to my good old 70D. Parallel card write capability is what attracted me, to test higher resolution.
Thanks a lot!
Sergio