Yep. Would have been a great shoe-in to support U3 on the S6 so you could do continual 4K recording rather than the 5min bursts they currently allow.
The 5 minute clips are nothing to do with the memory speed, its supposed to be issues with CPUs overheating.
Its a bit confusing actually seeing as you can keep recording 5 minute clips indefinitely, does a second or two of inactivity REALLY allow the CPU to stay significantly cooler?
Its also puzzling that the Note 4 suffers the same issue as the Note 3. I was really disappointed to find the 5 minute limit remained when I upgraded.
I also don't understand why Android (or at least Samsung) limits video recording length to the 4GB FAT32 filesize limit. Is it really that hard to dynamically start on a new file once you reached the file size limit?