Newbie question re: USB quality

Thanks to everyone who has guided me to this point that I'm able to even ask this question! I'm learning quickly about computer audio and right now using a USB thumb drive with DSD files plugged into an OPPO 105 (non-Darbee edition). I'm getting good quality sound that is certainly superior to rebook CDs.

However, I've seen it mentioned in various articles on audio websites that USB as the interface has various weaknesses. Usually, this is just stated without any mention of other options. What other ways would I be able to get audio files to my Oppo. I have a Macbook Air, but other than connection via USB from the computer, I don't know if any other way to get files to the Oppo.

Again, I appreciate your willingness to help a technophobic newbie.

USB 'done right' is still inferior to everything else. The world has passed USB by, guys. USB is officialy a dinasour.
I find your choice of descriptive words interesting, "dinosaur". Hmmmm..............................
I find his alternative even more interesting :)
I think it's ironic that it's argued above that USB done right is context of converting it back to S/PDIF :)

To the OP, yeah, two paths - one would be a USB-SPDIF converter from Mac to Oppo (loads of them around now). Another would be to double-down on improving the USB from the Mac with stuff like iFi iUSB, iFi iPurifier, a better USB cable.

It still comes down to what the Oppo seems to do better with. Try to do some comparisons across the different inputs to see if you can detect the baseline preferences it may have between optical, coax and USB.