I'm compelled to create an account instead of lurking. There should be no direct difference in sound quality due to hard drive or ssd or usb cables. The files are transferred to the Oppo as files and Oppo does the conversion from file in Oppo memory to audio and the differences in components discussed here shouldn't make any real difference. To put it another way, if you put your bank statements on a hard drive, flash drive, or SSD and then tried to read it over a USB cable, would you expect to get different results on the computer? Would your bank statements be more accurate if you used an audiophile quality USB cable? The data is transferred and then opened by Excel (or whatever) and displayed. The frequency at which errors would happen in the transfer from data source to computer would be extremely low. If you trust bank statements or homework to these storage technologies, then the audio files are just as reliable in terms of 100% fidelity after transfer.
With that said...I do own an Oppo 103 and switched to using an SSD since it seems my wireless network couldn't transfer high-res 5.1 files fast enough for continuous play (really choppy buffering problems like when you try to watch a video online and it just can't keep up and buffers). But the hard drive transfer rate over USB is much faster and more reliable than a crappy wireless connection. There is a big difference between not having sufficient bandwidth (buffering problems and no continuous play) and loss in fidelity or sound with continuous play (which should NOT happen).
The only other source of differences would be from some subtle interactions in stuff other than pure transfer issues (does the power source interfere in some way with other cables, etc.). Personally, I would suspect the impact is reasonably low for reasonable hardware. The most annoying sound impact that I can think of would be that some spinning disks I've owned I can actually here them spin and the heads move (you can hear on computer boot up...the ticking that isn't from the fan). This is worse if the data is fragmented. Defrag your spinning disks! :) SSD don't have the problem since there are no moving parts.
With that said...I do own an Oppo 103 and switched to using an SSD since it seems my wireless network couldn't transfer high-res 5.1 files fast enough for continuous play (really choppy buffering problems like when you try to watch a video online and it just can't keep up and buffers). But the hard drive transfer rate over USB is much faster and more reliable than a crappy wireless connection. There is a big difference between not having sufficient bandwidth (buffering problems and no continuous play) and loss in fidelity or sound with continuous play (which should NOT happen).
The only other source of differences would be from some subtle interactions in stuff other than pure transfer issues (does the power source interfere in some way with other cables, etc.). Personally, I would suspect the impact is reasonably low for reasonable hardware. The most annoying sound impact that I can think of would be that some spinning disks I've owned I can actually here them spin and the heads move (you can hear on computer boot up...the ticking that isn't from the fan). This is worse if the data is fragmented. Defrag your spinning disks! :) SSD don't have the problem since there are no moving parts.