If comparing Balao to type IX we should use at least the type IXC/40 or better the IXD2, to use boat types of the same era. The IXC/40 has about 3000nm more range, the IXD2 about 13000nm (other sources set IXD2 to 30000 nm at 10 knots) more range.
It has less torpedo tubes but the same amount of torpedoes stored (24). Speed is a little lower in the IX. The IX was not as large as the Balao and needed a lot less crew (~60 to ~85).
For extreme long range patrols the IX was better than the Balao.