Amplifiers and preamps are routinely so close to being a 'straight wire with gain' that measurements can be difficult. Loudspeakers are the most subjective component in any audio system. It can be very difficult to work out just why (and how) two apparently near identical designs can sound different. This is often despite the fact that many will show frequency response (both on and off axis) to be very similar, with many sharing one or more of the same speaker drivers as used by other manufacturers. There aren't many 'real' audio brands that will be truly awful, but there will be differences. This is reflected in commercial offerings as well.
We can be fairly certain that some of the published designs will sound very good, and others awful. It's highly likely that most of these will sound different from the others, although it's almost guaranteed that the designer will claim that his/ hers is 'better' in some way. A web search will reveal literally thousands of different designs, a great many of which are (at least superficially) quite similar. One of the most popular pastimes in the DIY audio world is building loudspeaker systems.
