Re: ACH1 & ACH2 pickups
I think your experience is really typical for a lot of Ibanez players. The ACH pickups are just okay. They're not terrible and they're not amazing. Mediocre.
I owned an ARC100BS with these pickups and like I said, it was fine when I was starting out, but as soon as I developed my ear, I could hear the weak points. Just a little muddy, lacking any tones that stood out in any frequency. Plain bass. Plain mids. Plain treble.
The V-series pickups in my RG20th were a step up from these; I really like the Ibanez stock V1/S1/V2 setup in that guitar. But DiMarzios would be another improvement.