No difference in sound quality, however:
The digipaks are standard jewel box size - they'll fit in your CD towers.
The mini-LPs (as their name suggests) are exact replicas of the original vinyl albums and have been re-sized so they can be the same original square shape. As a consequence, they are to big to fit in CD storage systems.
Verdict on which to get (if I were you):
The digipaks are more manageable, but fray quickly around the edges.
The mini-LPs are novel, but ultimately will end up in a drawer somewhere, getting scuffed. Whilst they are too big for a CD tower, the reduced LP size means that the re-sized text is often illegible. Worst of both worlds.
Go for Italian imports with jewel cases, or get a record player and acquire the original vinyl (all regulars on ebay).