There was a great big blockmount poster of this amplifier in the entrance of my local HiFi store with it's top off. The words were "Pioneer A-717- for audiophiles only". Then I saw one at the HiFi show with a perspex cover highlighting the parts inside. I'd already committed to the Sony ES route but I had a soft spot for the big Pioneer. So I added it to the collection as a 'rainy day' amplifier.
There's also the matching PD-7300 CD player in the storeroom bought at the same time- also never used- only opened the box to take out the supplied AAA batteries in case they leaked over the years.
Soon after, I was selling Pioneer and Yamaha, but within a year or two, the high end two channel was essentially finished and all things were AV. During that time, I went crazy buying all sorts of stuff at clearance/rebated dealer cost. Restoration of older gear became huge in my life and 'new' stuff lost its appeal, so there's heaps of sealed time-warp stuff to come out for air as I tackle my storerooms.
My plan is to pull out the interesting ones (well built) and remind people how it used to be for us.