I currently own a pair of fs208 Anniversary Edition and a pair of bs204.2, as part of a HT setup. Both driven with a Rotel RSX1067. I'll try to review them both below.
For starters, I should say that I have a 13 year history in pro audio and recording studio's. So I listen differently than most people and pay more attention than most to frequency spectrum balance. Where many people like big bass, I prefer deep bass that's well balanced with the rest of the audio spectrum. I also prefer a neutral, uncoloured sound with dynamics and transient behaviour that presents a believable, life like sound stage and a level of resolution that reveals low-level details. It should sound a great deal like it sounded in the studio.
Elac is a good product, but you have to dig the sound. I would characterize it as a bit "technological" as opposed to "musical". Elac is a thouroughly German speaker: well engineered and packed with advanced technoloy. Take the JET-III tweeter, for example. It's great, extremely quick and sounds fantastic. It's also found in other high-end brands, and even in studio monitors from Adam Audio, Eve Audio (I kid you not!) and Unity Audio.
There is a bunch of good technology found in these speakers. But on the other hand, Elac cut corners to save on production costs. For example: the entire cross-over of both models of speakers, is made with electrolytic capacitors - while everyone in the audio industry knows that even cheap film capacitors sound way better: more transparent because they are electrically quicker which translates to better transient handling.
The Elac fs208a has powerful and really deep bass (true 29Hz - I measured it) and in most cases doesn't require a subwoofer. With movies these speakers sound absolutely fantastic! Great dynamics, real deapth and slam in the low end, good mid-range resolution and a detailed and quick top end. And they'll go LOUD! But with music I believe they'll have to admit defeat to my smaller Dynaudio Audience 122's. Even though the low end isn't as well dimensioned in the Dynaudio's, the overall tonal balance is much more believable. The Dynaudio's sound more like music and less like good sound. Also, voices (and spoken word in particular, like dialogs in movies) sound much more believeable with the Dynaudio's. Male voices sound a little thin and disembodied through the Elac's.
The Elac fs208a's still are quite good speakers, but their frequency response is a bit "scooped": looks a bit like a smiley-face. Good, solid low end, fast and incredibly detailed treble, but in comparison the mid-range seems a bit recessed. When I first hooked these speakers to my NAD amp, I though "WOW!! Immense amounts of detail!" But after a while I came to realise it was just the tweeter that played way too loud. Fortunately Elac lets you adjust tweeter level by setting a jumper on the cross-over. So I set it down a notch. I still think it's a bit too loud, but I can live with it much better now. The bass, however, was a mess and all over the place: no definition, I wasn't able to distinguish between kick drum rumble and low bass instruments. I swapped my NAD T752 for a Rotel RSX 1067 and things improved massively. Much tighter low end, a little more extension and much more control. This implies the Elac speakers need a high quality, stable amplifier. But with a minimum impedance of 3.2Ohms, that seems only logical.
The bs204.2 is definitely a part of the Elac family: near identical sound (also "scooped"), although you can hear it's a smaller speaker. It has less power and extension in the bass range, a bit less resolution in the mid range and near identical treble. Obviously it handles dynamic peaks a little less well than it's bigger brother. But in smaller rooms, these small speakers can still conjure up a great sound.
I think Elac is a master in producing low bass from small speakers. Even for it's size, the fs208 plays lower than you'd expect. The same goes for the bs204.2. It sounds quite a bit larger than it actually is - especially at lower volumes. The downside is a little flabby and undefined low end. But if you use the supplied bungs to close the bass port, you'll be rewarded with a little more extension and a much better behaved bass response. The output in the bass range drops a dB or 2 in the usable range. But in my opinion that's a good thing. I do think the fs208a projects a larger, more 3D sound stage than the smaller bs204.2. Usually it's the other way around. But this might have to do with positioning.
All in all the Elac fs208 is good speaker. It's got a sound quality you (may) have (to learn) to like, but it has a few strong selling points. Personally, I prefer the more natural sound of Dynaudio. But I do reccomend a thorough listening session to anyone who's looking for new speakers. The newer Elac offerings sound very "hi-fi", but in a good way. A little more mid-forward than my older speakers. They're not as ruthlessly unforgiving as Dynaudio, but should still offer very much sound for a good price.