Just face it already, there won't be any superior Magian Staves until they mesh ToM into SoA content. I'm not going to burst your bubble with anything but -facts-. This tacks on considerable damage to T1 and T2 nukes, turning a Black Mage into a machine gun so to speak, churning out fast numbers with very little loss to MP. Seriously, to say that this and the Actinian Staff are inferior to a Magian staff is like a ferret (Magian staff) picking a fight with a rhino (soothsayer/actinian) with a pointy wizard hat on its head.
I'm sorry if people who made the Magian Staves don't like it, but sadly this is the truth and there's no avoiding it. It's impossible to stay the top dog forever, so save yourself the grief, shelf your staves until ToM gets upgraded, and then you can upgrade your staff over these so it'll be back to 'normal'
Assuming maxed MAB path, this staff can get up to INT+20 and MAB+65.
As far as MAB+65 goes, it's decent. If you have 89 MAB in gear/traits/etc. elsewhere, magian staves will offer more as far as that goes. For them to beat MAB+52, you need +49 or more MAB elsewhere in gear/traits/etc. (albeit more is ideal due to the INT and INT augments).
Capped Soothsayer staff doesn't quite match up for nuke damage vs trial Magian staves., (I've experimented). I see this staff and the Atinian staff being great for one's accuracy set, Meteor & Adoulin endgame to land enfeebles and make them stick. Both are great staves but for sheer damage, ToMs is where it's at.