WELL! I can offer some insights if you'd like.
Kibblestasty wanted a Psionic System which was somewhat different from the 5e Spellcasting system, but not -so- different as to be something you had to learn from the ground up. So her Psion has Power Points.
Her Psion has both "Talents" and "Psionic Spells" which you can spend power points on. Spending power points on Psionic Spells is basically like having spell slots where you need a certain number to activate a certain power/spell. While Talents are basically cantrips that you can spend Power Points on in order to improve aspects of the Talents to make them into "Regular Spells", essentially, for power-level purposes.
The Talent is an attempt to move away from traditional spellcasting entirely, while also playing into the Psychic with a Nosebleed. Instead of having spell points you roll your manifesting dice. If you roll below a certain threshhold, you take penalties and damage. Take enough penalties and you can't use your powers anymore. But that's okay! The damage will probably kill you before you can't use them anymore.
However... their powers are still basically just D&D spells.
The Korranberg Chronicle Psion has Power Points and Talents and Augments. Talents are literally cantrips and referred to as such in their individual text descriptions. Augments are Psionic Spells down to having 9 levels and a Power Point cost that directly maps to having a specific number of spell slots.
Only instead of upcasting with higher spell slots you "Intensify" a power directly by spending individual power points to gain more benefit from those powers. Lots of powers cannot be "Intensified" in the same way lots of spells don't really get much benefit from casting them at higher levels.
My Esper is a whole other ball game.
You get a handful of Psionic Powers as you progress. The powers themselves essentially function as Cantrips. You also get Psi Dice you assign to Augment a power in specific ways. Each power has a variety of different augments, and there are also "Basic Augments" which apply to every power (Like "Increased Damage")
Once you've decided how many Psi Dice to assign to a power when you manifest it, you manifest the power and deal with the results. Then you roll any Psi Dice you assigned to the power. Any Psi Dice that comes up a 1 or a 2 is expended and can't be used, again, until you recover it. If you roll the maximum value on a Psi Die, you can immediately recover an expended Psi Dice. You recover Psi Dice during a short rest by trading HD for them, and recover all Psi Dice on a long rest.
Your Psi Dice start out as d4s, but eventually grow to d10s. So you begin with a 50% chance of losing a Psi Dice when you roll it, but the odds eventually drop to a 20% chance.
There's also a class feature (Psychic Focus) that lets you choose one of the four disciplines that all powers are a part of to focus on. And if you roll a 2 on your Psi Dice with a power from the discipline you're focusing on, you can reroll that die.
Every power is either representative of a discipline (Empathy, Kinesthetics, Telepathy, Telekinesis) or a combination of two or more disciplines (Chirurgery is Kinesthetic and Telepathic, so focusing on Kinesthetics or Telepathy lets you reroll 2s on Chirurgery Psi Dice Augments)
It's initially fairly daunting at first. But it's also really popular, here. It was recently brought to my attention it's the most purchased A5e 3rd Party supplement which blew my mind.
