I like that Billagestudio is very user friendly for my team members to use as well! It's easy enough so they can add their own information without any help from me or anyone else at our office when it comes time to send out an invoice after we've completed work together in Project Manager (which helps us with keeping track of billing).
There are some things about this software which could be improved upon but overall everything works great!! We have been able solve all issues related specifically project management through using Pm Pro by Envision Technologies LLC Software-asd Service Company.