Well 9mmFu was kind enough to give me a box 4 to test. We had 7 level 50s, most with opertive loads but some hacks. Overall, I would say a lot of balance has been achieved. However, it needs tweaking. Resistance is just too much, ours and theirs. A non buffed power attack was doing 30-40 damage a hit to them, they were doing about 100-200 a hit to us. I think that that proportion is about right, but the damages have to be increased. The problem right now is that the box dissappears before we were close to done. The time ran out for us with 7-10 NPCs left on the last (3rd) phase. So my suggestion is to either, increase damage on both sides to speed up the outcome, or make the timer way longer.
It was taking us about 3 minutes a guy as a team of 7 when we were able to lure them away from the group, which get's very boring. I think it should be speeded up.