If SU(5) is false, then is SU(4)×SU(2)×SU(2) true?

We need a GUT before we can even begin on a TOE. My question is, when
was the Georgi-Glashow model shown to be false? Also, what tests can we
do on the Pati-Salam model to show whether or not it is true? I figured
that SU(5) was wrong from its start, since it didn't include both
normal 'flavors' of quarks. On the other hand, I predict
SU(4)×SU(2)×SU(2) to be true, as it can be worked to include both
normal flavors of leptons and both normal flavors of quarks. Hopefully
I will get actual discussion here.

-Matthew Paul Finnigan-

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