I cant decide either. On my power lock they've been on and off half a dozen times. If im wearing shop gloves I dont notice the digging in, but bare handed they arent the most comfortable with no covers. So... I dunno.
I removed the covers from the SOG PowerLock and PowerAssist almost immediately because they are more trouble than they are worth. The PPP doesn't even have handle covers. The compound action of the SOG pliers lets you grip items with less force than other multitools so the SOG handles don't hurt my hands.The PowerAssist's knife lock levers chafe my hands more than the handle edges.
The PowerAssist has only one handle cover and it is designed to stay on tighter. But, it remains a hindrance to fast tool access and the pliers can get stuck inside the opening of the cover. Covers, be gone!