The worst Talisman I've come across makes it so your controller sends out a pinging noise whenever you're close to power crystals, which are freaking everywhere. I guess late game if you're searching for the few you haven't collected in a certain area it could be useful, but for right now there's really no reason for that and it gets annoying.
Oh nice, I didn't even know there'd be stuff like that. What's the "worst" one you've seen so far?
Most of the "useless" talismans still do little things for you when you equip them, though. Some give health boosts, others make you consume less gauge while in gravity mode, others will increase the effectiveness of attacks, some make your gravity slide better... There are a wide range of effects, and most talismans have more than one effect.
You have three talisman slots total, and tons of possible combinations of effects depending on what you put in each slot, so you can really tweak things for your style of play. Also, a lot of side quests and challenges reward you with neat and powerful talismans, so that gives you an extra incentive to do those (in case the charming little stories weren't enough).
There's also the possibility to discover talismans or run into mini bosses while "mining," which is basically the GRush 2 version of grinding for currency. The mining locations are generally very beautiful as well, so it makes it less of a grind and more a pleasurable way to kill time and still be productive. Here's a snapshot I took from one of the very first mining locations, sitting on top of a giant statue:
I sat there for a long time just looking at the sky and my surroundings. It's shit like this that makes the game so hard to "rush" through for a review.