Sorry to say, but the damage gain from attack limit raise is not "immense". It is actually insignificant enough that it will not save you enough time in raids or grinds to ever pay for the cost. It exists only for bragging rights and nothing else. I doubt there's enough people willing to pay that much for mysterious shards to keep the price that high, for something that does so little.
My first impressions... - My stamina issue is god awful now. Insane reaper + stamina potion used to sustain 50 speed acceptably; I am constantly short on stamina post patch. - SP -> mana skill has a 25s cooldown, far too long to burn up your excess SP. Cat statue remains useless in raids after the first 15 seconds of a fight. - Damage output increased significantly, but still ain't remotely close to catching a skillfully played scythe or kai if you don't spam mercpot+ for stam refills. - Season 3 farm map grind speed improved a fair bit. Can now afford to burn mana on a lot of trash and still have mana to work with on bosses.
When arisha was new, back when top content is lvl 80 stuff, her high "risk" is in the form of being 2 shotted by raid bosses if you make any mistakes. lvl 80 and under int gear had been balanced with evie's mana shield and magic mastery in mind, resulting in arisha having really sub-par equipment (even with the focus) when compared to other meelee chars; making her feel a lot more unforgiving toward mistakes. Having 1.3k lower base hp than most meelee chars doesn't help.
Arisha's mechanics results in next to no downtime when fighting s2 bosses, allowing skilled players to constantly crank out damage, hence the high reward part.
This all went away with season 3. Standardized gear made arisha one of the lowest risk chars out there. S3 bosses also contain many moves that harshly penalize meelee chars with limited mobility, (tracer cooldown is too long to chase something like baldy or lugh for example). The end result? Arisha has low reward because far too often, you simply can't attack the boss at all.
And this is the current state of arisha: low risk, low reward.
PS: a huge portion of arisha's supposed dmg back when she was new is from temp shift glitching the scoreboard, and not her doing actual damage.