First post for me - finally out from the shadows! This forum has been priceless to me for the past 3 years.
I am posting this to ask whether I am missing something obvious, and if not I hope it will help others.
I recently bought a couple more CF cards for a wedding - yet another Transcend 32GB 400x and for my first time a Lexar Professional 32GB 800x. I have always (since 2004) bought Transcend but thought I would treat myself to a Lexar at double the price as I assumed it would have superior write speeds, not that I typically shoot long bursts of RAW, just short bursts. So I got it thinking it would just be my better, default card for future shoots.
On my 5D3 I was surprised that the Transcend was actually faster, yet cost less than half the Lexar. in 5 seconds I could write about 17 shots with the 400x Transcend but only about 14 with the Lexar 800x. The test was writing Large RAW to the CF, and no SD card present.
Since I have personally had no issue with reliability nor support for the Transcend nor the download speed to my computer, I wish I had known, because then I would not have bought Lexar at double the cost. Maybe there is clear information somewhere from Canon, but I must have missed it.