The Day and Week views are both broken down by hour, giving you a lot more room to see the details of your schedule. You can also use the pinch gesture to zoom in and out, in case you need to see more details all on a single screen. Meanwhile, the Agenda view shows only scheduled events, color coded, all in list form.
Creating new events via the app is similar to the experience on the Web. All of the appropriate fields are there, and there are options to invite people and schedule repeat events. The newest update to the app also added a color palette for labels and a revamped date-and-time tool.
Notifications are a useful part of the Calendar app, as they can be set with a custom ringtone and/or vibrate mode. There's also a snooze button that can essentially delay a notification for a set period of time. From the event page, you can even send a message to all of the event's attendees. Google Calendar comes loaded with a few quick preset message or you can create your own custom messages as well. I like using this feature to send a quick message when I know I'm running to a meeting.
One thing that's missing from the Google Calendar app is Tasks. If you use the taskbar on the side of Google Calendar on the Web, then you'll be disappointed to know that the tool hasn't made its way onto the mobile app. At this point, we're not sure whether Google Tasks will ever become integrated, or if it will end up being developed into its own standalone app. In the meantime, I would suggest picking up a third-party download like Tasks to get the job done.
Overall, the official Google Calendar app is a reliable, basic alternative to your device's built-in calendar. Outside of its Month view, it has an interface that works well and should suffice for most of your scheduling needs.