I know pip conversion got a lot of hate when it was added, and as someone who advocated for it on the forums in the past (on my older, now abandoned accounts) I know many people were strongly for it and many were strongly against it.
It had been discussed to the point where people were tired of hearing it by the time I threw my 2 cents in. So many repeat threads of people pointing out the problem with odd number spells and power pips. Plenty of people said it just wasn't going to happen. Obviously they were wrong.
I was happy when I heard they finally implemented it, but making it a late game gear stat and actually sacrificing other statistics in favor of it...I mean, I'm certainly not a fan myself.
I wholeheartedly believe that pip conversion should be introduced at the same time as power pips, and that, like with power pip chance, it should scale with your level, with the option to boost it with gear as you see fit.
Also, this whole higher number = higher percentage thing is questionable at best. Why not just have it be a percentage to begin with?