I played around with Ascetic in Besieged as MNK/WAR. Targeting the same Aerial Torpedo, I found that Ascetic, Howling and Asuran all appeared in a 50-damage spread in the low 400s with Ascetic at the bottom and Asuran at the top. This was all at 100TP, full TP return, no DA, Berserk active. When I stored up 300TP, Ascetic would never fail to deliver ~700 damage, exceeding Howling's numbers slightly at the same TP. Asuran, of course, remained in the 400s.
I moved on to a Troll Hoplite (PLD). I had Footwork active at all times for this target in order to compare Ascetic to DK. Interestingly enough, at 100TP/full return/no DA/Berserk on, Ascetic was doing damage comparable to DK (within 30 damage) with Footwork and Dune Boots most of the time. Any time they DA'd, Ascetic's would exceed DK. At 300TP, Ascetic's would always exceed DK.
Now I'm trying to make sense of all this. Given that Ascetic's critical rate varies with TP, there couldn't be an increasing fTP damage multiplier causing 300TP Ascetics to pull ahead. Additionally, Ascetic somewhat keeping up with other WSs at 100TP shows that a critical must be occuring almost every time. There were two instances of Ascetic falling under competing WSs by 100-150 damage, which I could only explain as non-crits. Even if these were non-crits, the frequency of a critical attack at 100TP remains high. At 300TP, I suspect both hands are almost certain to connect for critical damage thus giving Ascetic the edge.
So how is it that even DK+Footwork+Dunes was outdone by Ascetic on the Troll Hoplite?
When I used Ascetic in Einherjar during an earlier test, I had SV Minuetx2, Berserk, Footwork, Boost... an excess of +ATK at my disposal. Ascetic seemed unremarkable at 100TP while DK (although all DA'd kicks) ripped the chamber boss apart. On high defense mobs in Besieged, with only JAs and equipment enhancing my attack power, Ascetic met or beat other WSs. Does this mean Ascetic performs better than other WSs as pDIF decreases, similar to the increase in damage of a critical melee attack over a regular melee attack?
Of course, this could easily be a horrid fluke and I should feel ashamed for using Besieged as a testing ground since I couldn't account for things like Angon, Dia, etc.