Wakshaani, I really like what you did with it in 5E. While I was not a fan of how it changed in 4E (the skillwire thing, you can get Agility boosts elsewhere), it was still the go-to Initiative booster over Wired Reflexes. Now, each of them offer their own advantages and flavors.
Maybe they'll let you throw in an optional rule box (like gamma-grade) when the FAQ/Errata comes out that has a 4th level. THAT would be sweet!
And I disagree that I should not expect to port something from 3E to 5E. Does it require work? Sure. But to say it can't be done? Nah... What I'm basically doing is slightly higher Essence, much lower nuyen, mandatory drawbacks..., for what someone can get (or pretty close) with maxed out Muscle Toner, Reaction Enhancers, Wired Reflexes.
That being said, its really just a mental exercise. Most of this one boils down to, 'If I were a runner, would I want to spend the nuyen on said Muscle Toner, Reaction Enhancers, Wired Reflexes, or would I want to buy this and deal with the drawbacks?'
So far, I understand the Essence cost makes it no across the board. I originally intended to keep it close to the original and the new write up that stated the old was to expensive and invasive for widespread use. Nuyen cost has been dropped. If I drop Essence costs to 3,4,5,6, would that give some a reason to consider? What if the mandatory TLE/x was staged? The quality states 5-hits= minutes, so it could go (level+1)-hits= minutes.