Apart from the arguments already put forward for leaving it vacant, if I was buying, I would not consider an apartment occupied by tenants, fearing they might refuse to move when the time came, and I would be left in limbo while the owner went through the lengthy procedures required to get them out.
Of course they would have to move eventually (Whenever that might be), but why bother with this apartment when there are plenty of vacant two bed apartments available, even in desirable parts of Dublin, more than likely even in the same complex.