I like its ease of use as it is very easy to understand and implement, It also has many different ways you can integrate with other existing systems.
There are so many features that i am not sure what they would include in their next version but this one works great. Also there isn't much room for customization which could be an issue if your looking for more specific integration capabilities. We have been able to streamline our internal processes by using sensorup internally instead of having multiple 3rd party tools used.