The PX-708A was a good drive for audio extraction, probably significantly better than the PX-716 when it comes to scratched discs.
Double check your 708 - if it is a PX-708A2 then it can scan (PX-712A hardware inside). I can't recall for sure if it mentions it on the label, but I'm pretty sure they are identified by that name in firmware.
Another consideration - like all slot-loading drives the PX-716AL can scratch discs. It is the best designed slot-loader I've come across and doesn't use rollers like most. But any hard particles on the felt lips will scratch discs.
But if you do decide to discard the PX-708A, don't bin it. There are some of us left who would be delighted to give it a good home.