One thing I've learned since taking on repair work for the local guitar store here... (little background, they sell a wide selection of middle to high-end acoustic guitars there, in addition to electrics... it's probably an 80/20 split) but one thing that has surprised me is how many folks will buy a $2000, or even a $9,000 guitar and then conduct an exhaustive search for 'the right pickup system' for it. There is a LOT more variety now than there used to be in this stuff. The big name brands now I see, K&K, LR Baggs, Fishman still has a presence too. And they all have different levels of equipment. You could literally spend hours reading through specs of each product line.
I want to stress this next part is purely my opinion... it is worthless to everyone but me. There has never, ever been a pickup put on an acoustic guitar that reproduces what that guitar sounds like accurately. It is merely an approximation. Some are better than others. Some sound pretty good actually. But they will never reproduce the sound coming out of, and off of there. The best microphones in the world have a hard time with it. So you're making a compromise in the name of convenience... just know that from the front. Me, I kinda' like the way my guitars sound. I don't want to hear them differently. Again, this applies only to me. I do not assign it to anyone else.
As someone who has to work on them, the ones that impress me least are the guitars where the electronics are integrated into the instrument from the initial build. This is madness. Electronics become obsolete in seasons anymore. So it's time to upgrade, or something fails... and now you have a guitar with a bunch of non-working guts and molded plastic parts set into recessed cutouts. At least the aftermarket pickup systems can (generally) be replaced without modifications. I've made a set of templates for plugging these battery boxes, preamps, oval-shaped jackplates, etc with wood. It never looks 'right', but at least a nice guitar doesn't have a vacant hole. Most folks are happy with this fix, because it's just their gig-box anyway.
So hypothetically, if I had the kind of gig where it was absolutely necessary to plug-in an acoustic guitar... Element or otherwise, I'd definitely put something very simple onboard. Definitely outboard eq and preamp... nothing that required any batteries or any mass added inside. The least amount of wires and mess, the better.