Have there been upgrades to the Rega Apollo-R CD player through the years

I am interested in getting a Rega Apollo-R CD player and determining whether to buy new or slightly used.  My question is if there have been changes in the past few years, since 2014 or so to the model or updates that can be performed by uploads.  Is there a significant difference from an Apollo-R 2018 to a previous year. Is the Apollo CMD completely different.

Thank you,

I rather doubt it, but why not contact Rega directly?
Though you could also use the Apollo R and output to a DAC of your choice. 
That is what I do.
Thanks B. I will reach out to Rega directly. In the meantime, I went ahead and picked up a new old stock Rega Apollo-R. With the difference I can look for a nice DAC. 
I would suggest an Ayre Codex-lots available used for $1400 some lower.
Or, a Schiit Gungnir or Yggy. (Multibit)
Ahh - I am looking at the Schiits.  I just don’t know the difference with the regular and Multibit.  I will check out the Ayre Codex. 
The Multibit provide better sound reproduction.
Both companies offer upgrades to their products, which I feel make them good buys. 
DAC's are evolving quickly and spending more than $2K is, in my opinion, silly.