HOW-TO compair:
-Make a list of ALL possible features (in a database) of all the firmware so you have only a list with supported/unsupported/partly supported (or something else just what you like the most).
-Make an extra field in the database which contains the bugs.
Now you can make a site where users can select 2 firmwares and they see directly what features one firmware has over another.
It takes some time but it's defently not impossible.
When a new firmware comes out with new features then you can add the new features to your list and put at all the other firmwares: not supported.
Good luck with it
...
) Because i think this could be a useful tool...