GM: “You all realize that somewhere aboard this ship is a spy with the stolen information.”
PC1: “I’ll begin interviewing the colonel; he seemed a little reluctant to talk about his past.”
PC2: “I use telepathy and find the spy.”
GM: “The colonel begs you, ‘please, you’ve got to find my daughter before its too late!”
PC1: “I will examine her room, and look for clues. If I don’t find anything, I’ll start exploring those ruins we passed by a while back. They look like a likely place for her to be hidden.”
PC2: “I use clairvoyance. I met her a while back, so I should have a good idea of her in my mind.”
GM: “The colonel’s daughter has been bound and gagged upon the altar. The evil priest sneers at you. Between you and him are swinging pendulums with wicked blades, jets of fire, and spiked pits.”
PC1: “I unhook my whip and swing it towards…”
PC2: “I use telekinesis. Then I use mind control and command the priest to dance around the room in an Irish jig.”
Unless your campaign is nothing but one rolling battle after another, roleplaying is about problem solving using your wits and intelligence. Unfortunately, most of those kinds of scenarios are easily circumvented by the special effects of psionic powers. As proof, look at Bester’s The Demolished Man, where the rare but not super-rare existence of powerful telepaths have all but eliminated crime in the future. (It is an outstanding book, by the way. It won the first Hugo Award.)
It is also extremely difficult to adjudicate. What qualifies as a “surface thought” ? What will an NPC consider “something that are strongly opposed to doing”? One need only look at thirty years of rancorous debate around the working of charm person to prove my point.
The solution seems to be always to de-power psionics to the point of not being really compelling as a PC option or making them like every other spellcaster class out there. I’m thinking of the almost inevitable psionicist or quasi-psionicist present is every Simon Green novel he’s ever written. It’s usually a lithe, spunky woman who says something like “I’m trying to use my Vision to penetrate the Veil, but I am overwhelmed by images of alien horror.” In short, they become something like a walking detect evil spell.
I’m not saying that they don’t belong in fantasy novels or movies. If you notice, the above examples don’t reflect a certain genre (except for a bit pulp-ish in nature). My point is that, from a games theory standpoint, they are way more trouble than they are worth. Just relabel the sorcerer’s powers and call it a day.