We bought a digital piano with weighted keys when it became obvious that M needed one (that piano wasn't a nightmare to deal with) and we had the money after buying a van and paying for B's birth. And even though P pulled one of the keys up (middle D) and we haven't gotten that fixed yet... there are a lot of great things about a digital piano.
We can split the keyboard so M and I are playing unison at the same time.
Built in metronome.
Different sounds that motivate M to play sometimes that extra set of reps.
Head phones again because when M wakes up early she can, and does go in and play her pieces without waking anyone! Wonderful.