The A-88x is the rare big brother of the A-77x, which I owned at one point in time.
Having owned one of these units, I can honestly say that these were the last of the 70's era power and sound quality, as the A-77x was 100w RMS, and the A-88x was 120w RMS (very underrated I might add!). This was when Pioneer was experimenting with their cosmetic appeal, and the look would be carried over (mostly) into their Elite line.
While not part of the Elite series, they carry many attributes that made the Elite series a solid set of equipment, but retain the tank build quality of their 70's equipment. I really enjoyed my Pioneer A-77x integrated amplifier when I owned it, but it's biggest downfall was the corrosion in the micro switches, which are almost impossible to dismantle and clean. Alas, down the road it went, as I didn't know what I know now about electronics.
As long as your switches work great, I would continue to rock it - Pioneer certainly doesn't make equipment like that anymore!
-Jason