If you're looking for a solid, non-Google planner, you've found it in mOffice. It has a smooth layout and most of the features you love about Google--all in a neat package.
This app is designed to sync with your Outlook desktop program. It will also sync with a client called Mobisynapse, but that costs an extra $10. This app falls under the "Getting Things Done" category, which seems to mean it's optimized to make work convenient. As such, mOffice has a very clean interface that makes it easy to find the features and menus you're looking for. Adding new tasks and events is a breeze. There are almost a dozen different widgets you can add to optimize your workflow. It resembles Google Calendar in form and function so well that you'll wonder if it's not just a new skin for that app.
It's going to be tough for this app to pry people away from Google Calendar, but it won't be for lack of trying. This app has everything you would want in a calendar app. Sadly, it's creeping into a very crowded space when it comes to calendar apps. If you need a break from Google for some reason, give mOffice a shot. You really won't be disappointed.