Google Translate is sufficient until it isn't. Without a means to cross-reference, you'll never know if what you've read and understood is accurate, or if you just *think* it's accurate. Knowing what you know (and don't) is just as important as the knowledge itself. If you can reliably spot when they're wrong, machine translators are very useful.

I actually prefer other translators because they yield more predictable results. I can tell when ATLAS is wrong, and in many cases figure out exactly what the correct meaning would be without even looking at the JP. With Google Translate, the mistakes are less predictable and therefore harder to spot and interpret.