[SCRktkt]

Welcome to rendering. Here are some things to try:

1. Plan on adding depth of field blur in post. This will allow you to use a cheaper anti-aliasing, such as Box instead of Gauss or Mitchell.

2. Experiment with composite renders for shorter times. For many scenes, you can hide the characters, and run the final gather once at a high accuracy. Then freeze the final gather, and render the camera moving in the environment. In a separate render, using the mental ray matte/shadow material on the environment, render just the characters. The images can be composited and adjusted easily in post.

3. For your Arch & Design materials, dial down the reflection interpolation for everything you can.

If you need more help, post here and I'll see what I can suggest; images of your work will help.