I had the Phonak brand CROS behind the ear hearing aids for several months, but there is a constant interference problem that they have not been able to fix, so I had to give them up. They worked for a month and then I sent them back for fixing. They worked for 2 months and I sent them back for fixing. They finally admitted that it has been a problem for years that they haven't figured out. Ridiculous!
I basically liked the wireless CROS system, because I could hear much better with them. I did hear momentary interference from different sources, but overall I was used to them. It is inherent in the wireless technology to pick up sound waves from other places in this age of technology. The piece of plastic/rubber that goes into the good ear is very small and pliable and has holes in it, so it did not affect hearing regular sound for the good ear. After my ears got used to having something hanging on the back of them, they were not uncomfortable. I had to buy bigger winter hats because there was added bulk behind my ears. No problem with glasses or baseball hats.