Well, yes and no, mate.
Enanthate has a half life of 4-8 days, but Sustanon has FOUR different half-life's. This is how sustanon breaks down:
Testosterone Propionate 30mg stays active for 3-4 days
Testosterone Phenylpropionate 60mg stays active for 1-3 weeks
Testosterone Isocaporate 60mg stays active for 1-3 weeks
Testosterone Decanotate 100mg stays active for 2-4 weeks
As you can see, the Propionate is a very short acting test ester, while all of the others range from 1-4 weeks. In essence, the enanthate is a shorter acting test, but the sustanon is a smoother test, as it is time released.
Cheers,
KJ