The best situation is to get 4 lock cores and lock both sides of each bar. They are perfect for relaxing on the beach or just chilling at home listening to the Word or other relaxing sounds. No 3. But its performance was so impressive that I just couldnt ding it in a review. Love love love them! The rack indeed holds 6 bikes, but it is a bear to lift your bike off of the rack without knocking the other bikes off at the same time because the spacing between each bike is so narrow. The weather is getting warm now and even though I am at home due to the virus, I couldnt see wearing hot boots all spring and summer around the house, but I was willing to do it if it meant no pain. You can still hear some noises at certain frequencies but its not bad ANC. I cannot wear tennis shoes! The shoe has enough cushion for my feet and I can handle the hardwood floors after wearing heels all day.