I've got a StaplesConnect setup right now and I like it a lot. I tried SmartThings and Indigo on a Mac first and wasn't happy with the cost and user experience.
On the other hand the StaplesConnect capabilities are currently fairly limited. You can schedule lights to come on and off, and can set schedules for thermostats. I'm doing this with Z-Wave now. Manual "Activities" are possible too, so you can tap one button and have a bunch of stuff happen.
Programming is fairly limited though. There's no IF/THEN option (if this gets turned on, then turn these other things off for example). There is also no variables support, so you can't currently have a "Day mode" and an "Away mode" and have different stuff happen when in those modes. SmartThings and Indigo both offered lots of options here but again the user experience for programming and operating the system was complex and/or ugly.
On the plus side it looks like they're improving the service quickly. The UI is pretty good on web, iPhone, and iPad and pretty much anyone can operate the system without training.
The hardware that's available on their store is competitively priced even vs. Amazon and the fact that they curate the list is a big help.
They recently announced Insteon support is coming and even though I've deployed quite a few Z-Wave switches and dimmers I'm not happy with them for various reasons and may try some Insteon gear soon. If StaplesConnect can talk to them like they talk to all the other gear, I'd be pretty happy.
So my current opinion is that StaplesConnect is simple, highly compatible, reliable, and priced really well. The true test will be how quickly they iterate on the app with new features, and whether they get serious about presenting the hardware in their stores (it's mostly online ordering right now).