I can’t get gapless to work over a network on the Oppo. I think a number of devices struggle with this. USB sticks work fine as long as they are formatted FAT32, NTFS or ExFAT. As others say, you have to select gapless every time using the remote. It could be more elegant, for sure. Hard drives work well, but people need to bear in mind that USB powered drives may not work if they draw excessive power from the USB port. I have a portable Western Digital 1TB drive attached to my Oppo which is USB powered and works fine, but if I attach it to the USB port of my amplifier doesn’t work at all, whereas if I use a full size external USB drive with its own PSU, if works on both devices. My external drives are all far too noisy, so the portable one is fine on the Oppo.