What do you like best?
It's very easy to use, just connect your Google Apps account and you're set. I really like the insights you get. You can see any problem and if necessary you can solve it based on that given information. A backup function is good but a working restore is even more important! 2 years ago, I remove by accident the contact list on my new Android phone and within seconds this change was synced to the cloud and all my contacts has been deleted. Thanks to spanning I was able to recover that contact list with a few simple clicks!
What do you dislike?
A backup solution isn't a an application you very much (thanks god). If you have many (less active) users in your organisation the price for each site might be a bit high. It would be better if they would offer different accounts: small and bigger ones. Of course for different prices.
Recommendations to others considering the product
Always use a 3rd party backup solution for your data. Even Google can fail.
What business problems are you solving with the product? What benefits have you realized?
The Google Apps data for my organisation is safe. Even i the a Google server fails. I think this is important and gives me more freedom.