The following two images show the same text, rendered in 8-point Courier New in a standard Presentation Manager MLE control, with and without FreeType/2 installed.
The first image shows the results using the default TRUETYPE.DLL shipped with OS/2 MCP. The second shows the results using the FreeType/2 FREETYPE.DLL version 1.3.
As you can see, there is a noticeable difference in quality. It is particularly evident in the lowercase 'w', as well as in the string 'OS/2'.
The next four images illustrate the embedded bitmap support.
This text is a mixture of single- and double-byte characters, taken from the README.TXT file distributed with OS/2 MCP Japanese. I chose this as an example because the ultra-fine detail inherent in many East Asian characters means that perfectly precise rendering is essential. Hinting alone is often not sufficient for this purpose, especially at small font sizes, and so Japanese, Chinese, and Korean fonts often contain embedded bitmaps.
This particular font, Kochi Mincho, does not seem to work properly at all under IBM's TRUETYPE.DLL, so the first image shows the text rendered using the old FreeType/2 v1.1 release (which did not contain the embedded bitmap support). The second image shows the text under FreeType/2 v1.3.
The difference in quality should be obvious even for people who can't read Japanese.
For a more dramatic example, part of the same text from the MCP2 Simplified Chinese README.TXT file is shown.
The font in this case is Firefly APL New Sung (10 point). The first image shows the standard TRUETYPE.DLL; the second shows FREETYPE.DLL v1.3 (with embedded bitmap support). Once again, you should not have to understand Chinese in order to be able to appreciate the improvement.