Did you check out SIASTO (http://siasto.com), their Google Apps integration is unique. No one else has done as tight an integration through their Gmail gadget, which I use all day, to create tasks, events, and even document directly from my inbox.

They also provide an awesome and entirely unique Google Drive editor that lets me edit files directly within the SIASTO interface. We also leverage SIASTO's GCal sync to keep our calendars across my 40 person team to keep up-to-date with what's upcoming.

We would highly recommend you take a look at SIASTO. It's a great product and the guys are super responsive.