Well. I think both, DXO Pro and Capture One Pro, are great. I started with LR4 and am now an Adobe CC customer. For me personally I do not think that LR is on the same level as DXO or Capture One. Again, this is for me personally. I think that LR has the best library management and spot removal, but that is it (except for it's big brother Photoshop). I started my search because I wasn't happy with LR's noise reduction or the initial raw conversion. I initially tried DXO and I loved it, but I couldn't find a library system that worked for me. Then I decided to check out Capture One. After the learning curve I am completely satisfied with Capture One. I found that DXO and Capture One are very similar sans the library management. Both have excellent noise reduction. An added benefit of both was being able to use the clarity slider without the details of the image becoming blotchy. If there is a downside with Capture One it is spot removal. I became accustomed to using LR for minor issues and transferring to Photoshop for major spot removal. I don't see me dumping Photoshop, but LR is sidelined for now.
Again, this is what I have found for me. Everyones needs are different, so it is really best to try them out for yourself.