I have dealt with the sore backside issue for sometime. I have also purchased different seats and gel seat covers, tried bike underware, padded bike shorts etc. I have recently found that
Serfas Dual Density Saddles seat technology does most of what they claim with putting your sitz bones right where they should be on the seat making for a very comfortable ride. I now have them on both of my bikes and the sore backside days are over, completely. It has made my entire bike riding experience so much more enjoyable. Hope this helps!