First "real life" test with the box yesterday. Band rehearsal with a motivated drummer...
Is it loud enough? Yes, it is. Even with the tiny Eden WTX264 there's enough to fill the room. The efficiency is stunning. As they're 8Ohm boxes, at the moment there's just 180W to the amp. Still no need to run the amp on maximum. I dialed in more bottom end in comparison to before (with an Ampeg 410). No complaints. The sound is a bit more woody, bony, growly, vintage, with a very smooth and powerful low end. Definitely not a neutral sound, but extremly musical. And by far enough loudness to be ready for a moderate band or a club gig.
Will I need/get a second one? Yes, I will. First, I do miss a bit of air movement. It's all there but not as... surrounding(?) as I like it to be. Could be the placement in the room too, but there's something missing in terms of "wrap me in the sound". I also want to give the amp a bit more headroom (would be 240W on 4Ohm). And though the box doesn't moan at the job, it feels a bit edgy to go full power just on one.
Things I dislike: Besides the size of the logo (which is a bit too big for my taste), there's one thing that really annoys me: Due to the placement of the handle, the box cannot be dropped on the rubber feet directly. The corners have just tiny edge protectors that are not domed. Thus whenever you drop the box it'll land on the screws of the corner protectors, damaging the floor and/or the screws. Fortunately it would be easy to just put another set of rubber feet in, using the screws or at least the screw holes of the corner covers. Still an issue I would expect to be solved on such a high-end product.
Doing the math: Bass + Amp + Box < 20kg - can't beat the sound to weight ratio.