Spec-wise this device looks nearly perfect - it has most features an acoustic player could need (guitar / double bass). The design is really well thought-through by EBS. The EQ section is pretty easy to use and effective. It's nice to have a headphone out and an AMP-sim (for DI-out only).
However, I had two major concerns, which finally made me return the product:
First, build quality seems to be questionable. The device has a nice feature that lets you switch between channel A and B when only input A is connected. I did use this in the beginning. But after some days this stopped working, without any obvious reason. A/B with two sources connected still did work as expected. I really hope that this issue is an exception, however, I also read reviews from other customers having similar issues.
My second concern is with the preamps. They are pretty clean, very little hiss. However, they do lack headroom. This might not be a big issue if you have some piezo with lots of output. But with my Ehrlund EAP I had to crank it up, and then I easily ran into feedback (the frequency response doesn't seem to be linear anymore). Similarly, the mic preamp is not too powerful (tested with a Rode NT1A).
I compared the sound to a Radial Engineering PZ Pro. It's not that easy to obtain in Germany, alas, and it also comes at a different price tag (roughly double). The tone of the latter has much more clarity and warmth to it (probably helping here: it runs at 15V). Admittedly, this might be more important for recording than for live-playing, where you might not notice it that much. To improve headroom and sound of the EBS, ideally you would run a good preamp before the EBS, e.g. the Lehle Sunday Driver. Or you could just push the Volume after the EBS; the master-knob does that, but for the AMP-out only, for the DI-out you'll need to add gain in the mixing console.
Summing up, I would still say go for the EBS if your pickup is not too sensitive and you don't need the A/B-feature with a single input.