Canon T3i Lens suggestions

Thanks for your time..

I can find T4i with 18-135mm STM lens for $1000.

Going by earlier thought of getting T3i body ($500) + 18-135mm STM ($500) it would end up getting to the price of T4i. Will it be more logical option to go with T4i in this case?

Comparing 18-135mm STM to 15-85mm USM, what are the major advantages with 15-85mm USM over the later?