My verdict:
I definitely recommend seeing the band, even if you're only familiar with the singles.
There's something amazing about singing songs like Today, Tonight Tonight, Disarm, Zero etc as part of a massive crowd. Corgan seems up for it, the sound is good, the new guys look the part. The new songs don't strike you as diabolical, although of course they're not of the same standard as the originals. Tarantula is brilliant live.
If you're in half a mind about seeing them, go do it before Corgan changes his mind again.