I like how easy it is to use for both internal users as well external clients! It's very intuitive once you get used too using this software! This has been helpful when trying out new products or services we are considering purchasing!! If there was something i didn't enjoy about S1 its probably because of my own personal preference rather than anything else they've done wrong haha :).
We have really enjoyed being able to track our sales reps performance through Salesforce Chatter which helps us keep them accountable while also giving real time feedback/suggestions if needed.