You need neither for live poker. You need to know hand ranges and how to bet fold and how to not want to kill yourself playing live poker. Thats all.
That said, to answer your question, I think the consensus is that pio is a better overall application. It is truly solving trees, where my understanding is snowie is trial/error psuedo balancing. You can also node lock pio with specific ranges, whereas snowie is always assuming it is playing against itself.
For live, you dont need them. Although I have picked up some pretty interesting things from pio.
Which hand do you want to bet more on J
2
4
?
A
J
or A
J
?
Which hand is a better btn 3 barrel: CO open vs BTN 3bet on K
T
5
2
7
A
J
or 4
5
?
These are advanced concepts that pio can help you understand.
If you use the search function in "poker theory" there are alot of threads talking about both pio and snowie.