Champions Complete is very good. There are five things you need to watch out for.
1) Growth: This power has some issues in this edition.
2) Shrinking: Shrinking is now super-efficient. Be careful with the results.
3) Transfer is gone, replaced with Drain + Aid. This can get mechanically awkward at times. Be careful.
4) Damage Negation: This power simulates certain things very well, but if you're used to 4th, it slows down combat A LOT. Be careful when using it.
5) Skill Levels with Limitations: All skills are now general. If you want more specific skills (That aren't sciences, knowledges, professions, or places), you take a limitation for it. I've never been a fan of this particular mechanic, because it opens a very bad door, but you can feel free to make of it what you will.