side-by-side comparison of features and deficiencies that you think are important and why
Delphi doesn't support yet: 64-bit and ARM architectures, Linux, MacOS X, "native" iOS support(only via MonoTouch) and Android. This list can be continued, but other platforms not so important.
Stable version of FreePascal has some problems with 64-bit ABI(one problem which I got was fixed in FreePascal 2.5.1).
Sometimes Delphi generates faster code than FreePascal does, but this is not critical.
FreePascal can be used with object files from GCC compiler and this feature is useful for me(static compilation with native libjpeg(in future I want to use libjpeg-turbo with MMX/SSE optimizations) and zlib for faster decoding jpeg and png, also I can use static compilation with Chipmunk and libogg). Delphi can be used only with object files from Borland C++, but I didn't get success to build and use something else than zlib...