Well mine is an Onionchi at the moment and I only let the hearts drop to 2 empty ones once. The rest of the time it only had one empty heart a few times.
And I don't class that as being too bad seeing as I have real pets to look after aswell as my tamas!
I think it should be changing again tomorrow, so I will post again and tell you what it turns into =)
Being a good tama is your opion whether or not it is. This is a tama thats going through its rebellious stage and it loves to sing... very loudly. If thats what your looking for in a tama then its a good tama for you. i once had an onionatchi and they aren't bad in my opionion he listened well to me, but he did sing. alot.