Your 103 is "absolutely perfect" and "performs flawlessly" and you "love it." Have you heard the new 103? Even if someone can answer your question and has heard both units, it is just anecdotal and opinion.Technical Improvements on paper don't necessarily mean better sound. The only way to really know is to hear the new unit yourself.
Oppo BDP-103 vs UDP-203 audio only
I have a 3 year old OPPO Digital BDP-103 player that is still absolutely perfect. Love it. I use it for HT, digital coaxial audio for music and for multi-channel SACDs via its HDMI output. Performs flawlessly. However I'm thinking of selling it here on Audiogon and upgrading to the UDP-203 primarily for improved audio performance. The new 203 has upgraded improved internal DACs. The 103 has the Cirrus Logic CS4382A 24-bit, 114dB 192kHz PCM & proprietary unlisted DSD value dacs & the 203 uses AKM AK4458VN 115dB 32-bit 768kHz PCM and 11.2 MHz DSD dacs). I don't have native 4K TVs and have no interest in upgrading to that format. Has anyone upgraded to the UDP-203 strictly for audio performance only and has compared both units?