I suppose there are two angles to evaluate the card from; it's raw power and the game experience. I haven't played with the effect for a long time because of the second angle. I like the hidden information nature of Magic, and much prefer the 'snapshot' versions like Gitaxian Probe or targeted discard etc. The information was correct at the time you used your effect, but what could your opponent have drawn since then? Even if you are on the receiving end, unexpected plays or comebacks can be good stories and good fun. If every play is obvious and there is limited chance for your opponent to surprise you, I think that is detrimental to the fun.
Is it worth it from a power perspective? You are invested a card, so you need the information you give you at least a cards worth of value, preferably within the next handful of turns. That is pretty hard to evaluate on a theory basis. I guess it makes attacks easier to evaluate because you know whether they have tricks, or responses to tricks you would cast. You know if they have removal, so you can hold back your best creature until they use it on something else. I don't know... regardless, I just don't see the effect as fun if it is permanently turned on.
curious on the thoughts of this card as there hasn't been any talk about it.
Is it worth it from a power perspective? You are invested a card, so you need the information you give you at least a cards worth of value, preferably within the next handful of turns. That is pretty hard to evaluate on a theory basis. I guess it makes attacks easier to evaluate because you know whether they have tricks, or responses to tricks you would cast. You know if they have removal, so you can hold back your best creature until they use it on something else. I don't know... regardless, I just don't see the effect as fun if it is permanently turned on.
There's no possible situation in which your draft deck is made better by Telepathy instead of an extra copy of Island.