I’m with Ashendale. Eresh is a love and/or luxury pick; her biggest redeeming value is having an NP battery for farming, but her ATK is among the lowest of the low for her rarity, and it remains low even when you factor in the Lancer class’ 1.05% effective ATK modifier. It’s hard to recommend her for farming purposes when her ATK and her lack of NP upgrade both work against her.
I’ve decided to pass on both Abby and Hokusai for now since my roster is full of strong ST Buster Servants already, and Hokusai is way too conditional to suit my taste as far as I can tell. But your mileage may vary.
Jeanne Alter is a beloved Servant that I don’t think is quite as amazing as she’s made out to be. Incredible when you have few Servants and lack other strong Buster options, but no AoE means she’s not a good farming pick, and no common class advantage target means that she’s rarely the best pick for what she does do best. She can be a great all-purpose DPS, but she’s rarely needed later on.
Semiramis looks interesting on paper, but I suspect I’ll roll for her because I like her, not because I’ll use her that much. If you don’t already have a Buster AoE Assassin, she does fill that niche; however, like other Assassins her ATK is somewhat handicapped, and she has a sort of hybrid and very specific support role that would seem to make her a reasonable fit only for some Buster teams…in which case she may be competing for a party slot with some other excellent options.