Hi Michael,
Sorry for a slower response. Some of the Vanity103 owners reported that the sound has improved even further with the linear PSU mod of the OPPO player. Not by a huge amount, but there difference was definitely noticeable. I have no personal experience, just passing info from others, but I am happy to believe that. If you remove the relatively high power switching PSU with all associated noise and ground contamination it can only make things better.
As for the clock I am a bit skeptical. I haven't heard about anyone replacing the main oscillators on the OPPO mainboard and using the Vanity103 at the same time. Although this would definitelly make a difference in a stock player, I am not so sure about the Vanity103.
Hope it helps.
Regards,
Pavel