We have two product versions:

FeatureTime+ExpenseTime+Expense Project
SummarySimple Time+Expense  entryCapture and Process Time+Expenses, extensive Reporting, Billing
Typical UseReport time spent on Accounts, OpportunitiesManage Project progress
Salesforce EditionProfessionalEnterprise
Enter Time
Enter Expensesbasiccomprehensive
T+E Reportsmanual, basicautomated,
internal and customer approval
Projectsbasicplan - actuals - current 
Project Management-comprehensive (Gantt, ...)
Resource Management-comprehensive, billing + cost rates
Invoicing-fixed price, time+material
Payroll Interface-multiple payroll processors, periods
Time Off-comprehensive
Utilization-resource utilization
MobileSalesforceSalesforce and dedicated