EDIT: Okay, so this is kind of irrelevant now with the buffs to heavy weapons. I'll go calculate Atterax vs. Scindo Prime + Manticore. My initial prediction is that Atterax is going to have its buttocks thoroughly spanked.
Hysteria - Dragon Nikana vs. Atterax damage calculations[]
Pre-hysteria base damage (pressure point, spoiled strike, steel charge):
Dragon Nikana: 85 * (1(base)+1.2+1+0.6) = 323
Atterax: 45 * (1(base)+1.2+1+0.6) = 171
Hysteria base damage (assumption; +100% power strength):
Dragon Nikana: 300 + 323 *(1.75*2) = 1430
Atterax 300 + 171 *(1.75*2) = 898
Hysteria crit calculations:
Dragon Nikana:
Base crit stats(T.Steel/O.Shat) = 0.15%*1.6 @ 2*1.9 = 0.24 @ 3.8x
Hysteria total crit chance = 0.24+0.25 = 0.49
Hysteria Low(100%)/High(200%) crit chance split:
2/5*0.49 @ low = 0.196 @ low
3/5*0.49 @ high = 0.294 @ high
Hysteria crit damage multiplier = 3.8x @ low, 7.6x @ high
Hysteria crit average extra damage multiplier per attack = 2.8*0.196 + 6.6*0.294 = 0.5488 + 1.9404 = 2.4892
Hysteria crit extra damage average per attack = 2.4892 * 1430 = 3559.6
Atterax:
Base crit stats(T.Steel/O.Shat) = 0.25%*1.6 @ 3*1.9 = 0.4 @ 5.7x
Hysteria total crit chance = 0.4+0.25 = 0.65
Hysteria Low(100%)/High(200%) crit chance split:
2/5*0.65 @ low = 0.26 @ low
3/5*0.65 @ high = 0.39 @ high
Hysteria crit damage multiplier = 5.7x @ low, 11.4x @ high
Hysteria crit average extra damage multiplier per attack = 4.7*0.26 + 10.4*0.39 = 1.222 + 4.056 = 5.276
Hysteria crit extra damage average per attack = 5.276 * 898 = 4737.8
Hysteria total average damage per attack (base + avg crit bonus damage per attack):
Dragon Nikana: 1430 + 3559.6 = 4989.6
Atterax: 898 + 4737.8 = 5635.8
Conclusion: Atterax average damage (and thus dps) wins by a significant margin. Because crit is OP.
I also quickly did the calculations for +129% power strength (max blind rage and intensify), and Atterax is still significantly higher.