My experience is with a Plus and an Ultra, both 8-10 years old:
The main issue was the volume control, which blasted when barely cracked. I trained many different methods to employ them, to no avail. I had them with 3 different speakers. It took years of advertising them FS until someone bought them for his Video system, which is what the company originally was based on. So, if you're looking to use them in a channel system ask before you buy
hth