I have a ton of canning rings some are in good condition and some are in bad. I am not sure why it makes a difference in how the bands make a seal but I can tell you from experience that if they are rusty they will not allow the lids to seal as well. Especcially with Tattler lids.
Make sure you inspect your bands prior to use and take out any with rust on them. I save mine for in case of emergency as they do seal part of the time but you will have about a 30% failure rate if you use them.