*[[X-Mass]] IDE/PATA mass-storage with [[Nova]] NVRAM/RTC or [[Symbiface II]]. It is the historically-plausible solution (the IDE/PATA interface was created in 1986). But it's a lie as the IDE interface was effectively introduced on the CPC with the [[CPC-IDE]] prototype in 2004, the Symbiface II being available in 2006. Symbiface II offers PS/2 mouse support, which is again not historically accurate.
*[[Albireo]], [[M4 Board]] and [[Symbiface III]] are the modern solutions that feed the CPC a direct file view of the mass-storage instead of a sectors view. So the FAT filesystem does not need to be handled on the CPC itself. Which means there is no need for the Nova NVRAM. It's overall a simpler more convenient approach but that means throwing away historical-accuracy completely. On the other hand, it is definitely more future proof.
*Albireo proposes an USB port which opens a can of worms as it nullifies what it means to be a CPC. It provides low level access to internet via SLIP which mean having the IP stack on the CPC side instead of it being done by the peripheral like in the M4 board, and having a server gateway so it is not convenient at all. Also no RTC onboar onboard the Albireo which mean another peripheral is needed for it.
*M4 Board is [https://unidos.cpcscene.net/doku.php?id=en%3Aannexes the fastest measured solution for mass-storage on the CPC]. It is a very complete and convenient solution with RTC and wifi network and very future proof. But that means sacrificing all historical ressemblance as the M4 board does all the hard work for the CPC.
*Symbiface III possess an onboard mp3 player. Are we still talking about Amstrad CPC here?