Having played with Technomancy against a fully mechanised Iron Warriors list, I can confirm that it's garbage. Best thing I got out of it all game was my phone autocorrecting Wrath of Mars to Wrath of Arse, which was both hilarious and accurate.
From closer analysis of the others, they're all very hit-and-miss, fairly shitty disciplines - a big part of which is crap Primaris Powers. With Divination or Malefic or Telepathy you can roll on it with a Level 1 or Level 2 Psyker and if you fudge the roll, you can still sit there, donate warp charge and throw out Psychic Shrieks/Presciences/Summonings. The Space Marine disciplines? If you're on Librarius you're irrelevant without Null Zone or Veil of Time, for Technomancy you need Warpmetal Armour and if you're allied in to a faction that actually has good tanks then the repair and POTMS ones are decent enough (although hardly impressive); Fulmination has better-Levitation and the ol' Switcheroo (which is totally worth it just to get out of combat with a relevant unit, it's basically auto-Hit and Run) with the other powers all being universally garbage (most Psykers don't really have enough the statline to make Electric Fists truly scary, bar lucking out with a Librarius Conclave to stack it with Warp Speed at which point you can muscle wizard your way through a whole squad of Orks or Gaunts and laugh inanely). Geomancy is probably the best; Landquake's reasonable as stopping Run and Flat Out is actually something Eldar will really hate you for, and is a useful utility power in a lot of situations (fuck you, Orks, you don't get your racial bonus!), Phase Form is Perfect Timing that can be cast on vehicles or other squads that got isolated and need the bonus, and therefore very powerful; Worldscape I'm not sold on as you need to fit into a terrain piece, have an appropriate terrain piece to hand, have enough dice to cast it and all the other powers you need (WC3 isn't hard to do for a Librarius, but taking 4 dice out of your pool makes it a big opportunity cost against casting Invisibility, Prescience, Veil of Time, Endurance, and other powers you probably want to have active), not to mention you kinda need to build around it.
If you want to use the Space Marine disciplines, bring Tigurius or Loth, because otherwise you're going to end up with a useless dead weight Librarian most games who'll sit on his ass with a Haywire beam and a 'you might not get to fire your pintle Heavy Stubber' malediction.