How are sharper image SHP920 wireless headphones?

I just bought two pair this afternoon on clearance. There was significant interference from my digital converter box, but that lessened and then disappeared as I used them... this might be due to the unit changing its broadcast channel each time I switched it off and on. At first interference changed depending on where I placed the transmitter, and if I was in motion, but I'm finding it hard to duplicate that... sound is mostly now stable with at most a single glitch when I move substantially to a different spot. The sound is quite clear, but certainly not audiophile material. Construction quality is clearly cheap, there are few size adjustments that can be made. The inside of the headband has sharp plastic that can mildly hurt if you push or pull it down... but the weight of the headset is not enough for that to happen by itself. They are light weight. Overall I find them comfortable.

I did not find out until after buying them that they function as an FM radio in their own right... the only channel control is one button to reset tuning to 88 MHz, and another to advance up to the next channel that gives reception.