Full spectrum, hassle-free
Like many guitarists who primarily play stage acoustic, I spent over 3 years obsessing and fussing over getting the right stage tone. I tried multiple systems, and asked countless other guitarists I met what they were using. I've heard people with passive soundboard transducers, undersaddle pickups, and soundhole humbuckers sound great, but then I'd hear the same system disappoint in other environments. I wanted a system that would give me a good balance of accurate tone and "plug-and-go" simplicity.
Enter the Anthem SL. My tech installed one into a repaired/restored Martin D-15 "project guitar," a couple weeks before we hit the road for a 30-city tour. The results were stunning. We played rock clubs, listening rooms, coffee shops, pubs, and a handful of open mic showcases. Most nights I used my LR Baggs para DI, but some nights I just used whatever DI box was available on stage. Every night my D15 sounded big and full, with just enough "air" to make it feel like a real mic'ed instrument. You can run the anthem quite loud without feedback, too.
I've tried both the full Anthem and the Anthem SL (and have traveled with both). In all honesty, I like the SL better. Rather than having a gain setting and a blend pot (as in the full Anthem), the SL offers a mic gain adjustment (relative to the fixed pickup gain level), and a single volume pot. Set it, forget it, play, no fiddling during a performance. IMHO, there's not much reason to want to blend more pickup into the signal. Also, the control section of the SL is a fraction of the size of the full anthem's, meaning way less "stuff" mounted beneath your guitar's top, allowing it to flex and vibrate as freely as possible.
While I would not do a recording session strictly DI with the Anthem, it has definitely saved my butt in recording situations. For one project, I was a session guitarist in a live room with a cellist and vocalist, and bleed was a necessary reality. During mixing, we were able to utilize the direct signal of the Anthem during small spots where the mic'ed guitar signal couldn't be used. The recording engineer noted that the Anthem SL was the truest DI guitar sound he'd ever heard. Also, if you are playing live and capturing a board feed, the DI signal of this pickup is far superior to anything else I've heard come out of a DI-only live recording.
I now have three instruments with an Anthem SL installed. The Martin D15 dread, a Waterloo WL-14 (similar to a Gibson LG), and a Blueridge dread. Since the Blueridge was something of a backup guitar, I installed the SL myself, and it was a piece of cake. Used a typical power drill for home repairs, and a step drill bit with some painters tape over the endpin hole.
Great system, super consistent, noticeably hi-fi, and affordable. If you have a guitar that you love, pop an SL into it!