The primary benefit of an mDot site is that you can customize your mobile user experience however you want, without having to compromise either your mobile or desktop experience. You can customize your Call-to-Actions to be mobile or location specific, the menu to only display mobile-centric pages, or content for micro-moment or voice search.
Home Depot’s desktop experience features bigger imagery, and puts more focus on navigation and additional financing information.
Home Depot has a separate mDot site to emphasize location-based featured and streamline the site search experience.
Because an mDot site has its own URL, it does not share link juice the way a responsive design website would across multiple devices. However, mDot site design and optimization can improve your mobile conversion rates. Again, this has to do with being able to optimize for the experience without having to compromise UX across on other devices.