One point of edge is a 33% chance to turn a fail into a hit, or an 84% chance to remove a single glitch, with a 33% chance of that non-glitch to be a success. +/- 5 points is 25% more chance to succeed or fail in D&D, and varies based at target number.
One edge to lessen/not glitch seems like a pretty good spend to me.
Spending 1 edge to re-roll 1 die does have exactly a 67% chance of failure, that's a mathematical fact.
It's also a 33% chance of success as well, in addition to an 84% chance to avoid a glitch. Also mathematical facts.
We can also call that a 67% percent chance you wasted an edge. As for glitching, if your pool is large enough the chance is low enough as to be irrelevant, and if your pool that high and someone does the 5 option turning one glitch isn't actually likely to save you. So that math all just says failure.
And if you're pool is low that could save you from problems. You know if someone has turned your glitch rate to 33% before you choose to reroll (or even roll) a die, so you probably shouldn't do so unless you need to. Situations ya' know, that's what a lot of rules are there for.
Wasting Edge doesn't seem nearly as bad in this coming edition as it does in the current or previous editions, seeing as how you can get them back pretty quickly and can only have a max of 7 at a time. Besides, the QSR seems to say that you can only spend Edge on one effect per action, but doesn't say you can't spend it multiple times for a single larger Edge effect (ie: spending 4 Edge to reroll 4 dice).
We've also been focused on just rerolling a single die on our characters rolls, and the boost simply says Reroll one die post roll. What if we can force that security guard that just got a lucky roll to reroll one (or more) dice. You're listed 67% failure rate works in our favor!