Classic Reports may be plain, but they meet most needs and can be easily exported to a variety of file formats. You can also create your own reports more easily than with the modern style reports.
Some will consider the Modern Style reports more attractive. They can be more difficult to use if you want to create your own reports. Try them out.
A picture can be worth 1000 words and Church Secretary for Windows include a variety of gaphic reports, dashboards, and more.
For Attendance and Contribution Reports it is common to filter on a range of dates. This version makes that even easier.
Easily create reusable Mail Merge Templates. Many uses. A special kind of report. Launch from a grid to print for selected records.
I find it easier to create charts using the Dashboard designer than the Chart Builder in the Report Designers. Plus, dashboards can be made interactive easily.
For many files, like Contributions and Attendance it can be useful to analyze data with Pivot or Cross Tab tables and Charts.