Accello is a comprehensive solution. It supports cross-paradigm automation. So you don't need to invest on multiple tools for enterprise-scale automation. You can use your existing staff (business users / operational staff) to do RPA using Accello instead of hiring a pool of developers.
Accello is flexible. It allows you to create custom commands using external Java, Sh, and Bat files. You don't need to rely on the tool vendor for every small customization you'd need. Furthermore, it's cost effective to scale up or down as your business needs demand.
To yield maximum benefits, RPA projects need to be approached as agile initiatives, with a focus on automating a business process with minimal effort.
A use case with a well-defined, standardized process can easily be automated within a matter of weeks if the chosen automation tool provides the required simplicity and flexibility.