DxO can be used like a plugin to Lightroom. Or one can us DxO to batch convert images to tiff files for import to Lightroom. No matter what, Lightroom has to convert the RAW files, through its own algorithm (Adobe Camera Raw). Photoshop also uses ACR. A RAW converter is propriety and have to reverse engineer the RAW conversion, and in the process get different colors or information than what the manufacturer might produce.
I use a Nikon, and Nikon's RAW converter is NX-D. It can do a good job, but it is clunky, and slow, and lacks features of DxO. I find DxO does a fine job comparable to NX-D with colors, but with the noise reduction and clarity features, it can produce better images. Images seem to come out better than when converted in Lightroom. Lightroom seems to produce a softer image but that can be adjusted, but the colors will start out different coming from DxO (or NX-D). I get better control over shadows and highlights. (but not all the time, it can really be image dependent) Lightroom has a dehaze feature and the non-cloud can get presets for dehazing, but I find DxO gets a cleaner overall result. As for reducing noise, I prefer DxO to Lightroom
I would say the consensus is that DxO does a better job than Adobe does within Lightroom or Photoshop. It might not be the best converter and its chief competition for RAW converting would be Phase One's Capture Pro (but cost a lot more at $300 because it is also does what Lightroom does).
I would not buy DxO as an alternative to Lightroom, only as a compliment. Lightroom can produce and fix images very well. DxO just helps by bringing a more crisp image to it. I am not a professional photographer so I have not got into batch conversion. When I am using Lightroom, all my images go there first, and images I like, or images I hope to fix, go to DxO. I might be working on an image, then decide I really like it, then start the whole process over after sending the original file to DxO) It is an extra tool, and even at 50% off at $99, can be considered pricey - but its still a great tool. Just about any plug-in for Lightroom is going to cost that. Lightroom can produce perfectly acceptable images on its own, DxO help by helping you to subtlety start off with a better image.. Personally, I don't think the entire suite is needed, unless you are into the filmpack, and do not like what Lightroom presets will produce. And for Viewpoint, I do not have an expensive wide angle type lens (nor do I do heavy architecture work) that I felt a need for it. DxO Optics Pro 10 itself is a good buy and comes with its own lens distortion correction (have to go to their website to see the camera and lens combo - but they are very extensive and do a lot of testing). I don't use DxO for every image. And it won't improve every image either.
I would do this:
Download a trial of DxO, Download your manufacturer's conversion software. Select 10 RAW's. Convert those raws into 32 bit .tiff images in Lightroom, DxO, and camera's software. Then compare them, and compare them to how well you could enhance them in those applications.