I've used DXO since v6. It has come a long way, in terms of usability, since then. It was awfully slow back in the v6 and 7 days, but now takes advantage of GPUs as well as processing algorithm speed ups to make editing a lot less sucky. It does not force the user to keep databases or engage in asset management like LR does. You can simply navigate to a folder of images a start doing your thing. You can also use "projects" which permit you to pull in images from several different folders, essentially creating a virtual folder of all of these images.
DXO has always been known for high quality raw conversions with excellent tools for optical correction. If you have a camera body with supported lenses, then you will get, should you choose, automatic optical distortion correction and sharpness falloff correction. DXO correction also includes anamorphic volumetric distortion correction for wide angle lenses, as well as a powerful perspective distortion correction tool for keystoning, etc.
New for v9 is DXOs PRIME noise reduction for very noisy images - this NR takes a long time to apply itself, so you will probably use it sparingly. Test it on some noisy images that you thought were unsalvageable and see if it makes a difference for you. The "regular" NR is terrific.
Tonal tools in DXO v9 have also been expanded to include highlight recovery, shadow boost, etc in addition to the Smart Lighting tool present for many iterations of DXO.
If you chose to purchase it, you can also incorporate (unlock) DXOs film emulation tool, Film Pack, which offers many positive, negative and black and white film and film grain emulations. One nice thing about DXO is the ability to apply other camera profiles to your images - you can shoot with a Canon 5DII and apply a Nikon D800 profile if you choose.
Etc. Etc.
DXO is not for everyone, but give it a chance and see if it fits into your workflow. It applies a base, automatic per-image correction to your images as a starting point - many people who use it like this look straight out of the gate and tweak the result very little. Others go much further with their images.
DXO does not support local adjustments - as far as I'm concerned, that is what Photoshop is for. But people who like the self-contained, one-stop-shop editing environment of LR will probably not like the absence of pixel editing in DXO. DXO tightly integrates with external applications, and, because it is not a DAM-type raw converter, the application is not tied to round-tripping.
People sometimes gripe about DXO's working space - it is, as far as I have read, AdobeRGB, versus LR's MelissaRGB (pro photo-like). You should decide if this is a problem for your images.
kirk