I can read/write to them on the PS3. I have successfully made a backup to both a 128 GB microSD-in-MemoryStick-slot and a 1 TB microSD-in-CompactFlash-slot. Obviously also a native 1 TB SD in the SD slot.
The "SD to Compact Flash" adapter is some cheap generic one off Amazon that claimed SDXC...
Update: I am sad to report that while the SD card slot supports a 1 TB SD card formatted FAT32, and the Compact Flash slot supports a 1 TB card formatted FAT32 (via an SD-to-CF adapter,) the Memory Stick slot only supports up to 128 GB. The biggest native Memory Stick ever made was the 64 GB...
Alright, I just tested.
A CECHA-01 running stock 4.89 can recognize SD-XC cards just fine. The only limit is that they have to be FAT-32 formatted; while the "standard" for SD-XC cards is ExFAT. My PS3 happily recognizes my 1 TB SD-XC card just fine reformatted as FAT-32, and will play photos...