I am not familiar enough with the grinders to be sure, but expect they will be very similar, and from my reading, very capable.
Advantages of the combi uint are smaller footprint, only one power connection required, cheaper overall than separate units. And you can use just the grinder or just the brewing functions if required.
Disadvantages are that if one half requires service/repairs, then you dont have use of the other half while it is away, (but this should be a rare occurrence), however compared to a separate grinder, the beans can get heated while in the grinder due to relative proximity to the boiler, which you can minimise by only adding beans as you require.
With a separate grinder you can add more beans than you require, to encourage better grind consistency, (may be more of an issue with flat burr grinders than this particular unit)and after grinding, tip out leftovers so they can be stored more appropriately.