[jseth]

They are each the same system, with different preamp modules... both have an under saddle transducer, the Element, and both have a small microphone that affixes directly to the bridgeplate, the True-Mic.

The primary differences are the SIZE of the preamp module/control unit - the SL is slightly bigger than a Blue Chip pick, while the full Anthem has one the size of a small piece of cheesecake (you'd need to check the bracing around the soundhole of your guitar to ascertain whether that big one will fit... and the ADJUSTABILITY of each unit; the "full" Anthem has far more ways to adjust the sound from each component, while the SL (Slim Line) only gives you a way to set the balance between the Element and the True-Mic. With the SL, the Element reproduces primarily the lower bass frequencies and there is no way to change that setting; with the full version, you can designate the Element to reproduce full-range, thus enabling it's use as the only means to amplify the guitar... this could prove useful in a full band setting at higher volumes, where the acoustic guitar is may be more prone to feeding back...