Recorded 4 channels at 24/96 with my 64gb PNY SD Card on 12.18.15 and had another flawless evening with my 70D. I ran an m10 as backup out of my VMS02ib, but didn't need it in the end. Figures the ONE time that I didn't run my m10 as backup[festie this past summer], my 70D choked and I missed a whole days worth of stuff. But that was also with a microSD Card that I had NEVER tested before.
I think the deal with the 70D is having a compatible SD card. Seems like once someone gets a proper SD Card, their problems disappear!
I think that pretty much sums it up. For those people who have used incompatible SD cards, the 70D has been frustrating and unreliable. With a compatible card (be it one tested by Tascam or not), everything seems to be OK.
While it may be annoying, the 70D is particular and/or more demanding with SD card performance. We may never know why since Tascam is unresponsive, but the fact is you must be careful about what card you're using or you risk running into problems, even at less than 24/96. Definitely start with the recommended media list, but you may also find untested cards that perform well (such as Bean and some others having good results with some PNY cards). Just be sure to test such a card very thoroughly over several uses before you use it for a recording you really care about.
Reports of record errors with the 70D are becoming few and far between lately. That could mean:
1. More people are now using cards on the recommended list (and again, it's fair to note there was no list for a while after release).
2. The 1.12 firmware update somehow improved things.
3. People are using the 70D less often in favor of different recorders, for fear of having a bad recording.
4. Everyone's tired of talking about it / doesn't care anymore.