Odd thing to post now, but having been going back and forth between GoS and DoD on my own time, I thought a bit about the general idea of party survivability between the three games, and I have to say, for all the bullshit GoS throws at you, most of it can be tanked, both with and without Alice. I daresay of the three games, GoS has the most ways to deal with heavy damage. Second best would be NoR, since EVA buffs, MDEF buffs, and Akyuu's skill are all really good ways of tanking a variety of damage. DoD... doesn't give you much. You can deal with a specific element with Jammer, Benevolence Wall on a tanky character combined with either Physical Defense, Magical Defense, or Aegis Defense can deal with other stuff, but most of the time it's actually fairly difficult to get a good defensive party. Especially since buffs in this game are the worst of the three games. I barely notice much of any difference when one goes up, yet it's very clear there's an effect in GoS and NoR.
Just felt like posting a minor analysis of that kind of thing. Long story short, when it comes to dealing with bullshit damage, GoS > NoR > DoD on that front. Which is funny, because the frequency of bullshit damage is roughly... GoS > DoD > NoR.
As for the ultimate weapon skills, there's information on the blog-like wiki about them, including all the percentages (they're very low), but not so much on their effects. I can post the item.srsdb.csv if you want to take a look at their descriptions, otherwise uh... I dunno. Also yes, still on hiatus, trying to play NoR with a separate monitor that hates high resolution games is suffering.