I have a TA-1A and a TA-3A. I'd classify the TA-1A as a satisfactory entry level receiver (I was in college when I bought mine new in the mid-80s). It has been relegated to powering the passive sub in my HT rig for years now, does a fine job there, and hasn't given me any trouble.
The TA-3A is a different beast altogether, being a STASIS design with ample power and high current. I used to have it running some Maggies and it was no sweat. After I switched to a different amp it was in storage for quite a while until I realized I had the makings of a whole system laying around. I set it up in the bedroom with a B&O RX-2 and a pair of KLH Sixes, and sometimes I think it sounds better than my main rig, which is probably worth at least 10x as much.
Their biggest weakness is a propensity for melting some solder joints on the internal PCBs at this age. My TA-3A did, and it took me forever to find the right tech to fix it, but now it's perfect and sounding fantastic as always.