Rose::DB::Object is supposed to be a good performer for when you really need it. I know nothing more about it.

I do :) Yes, Rose::DB::Object is many times faster than Class::DBI during almost all operations, but plain DBI is, in turn, many times faster than Rose::DB::Object.

I recently posted the results of a comparative benchmark of several RDBMS-OO mapper modules, plus "plain DBI." Although Rose::DB::Object is the fastest RDBMS-OO mapper module by a significant margin, plain DBI is the fastest alterative by an even larger margin. The fact that DBI is the fastest is probably no surprise, but the size of the margin may be.