I assume you are referring to using Kodi add-ons like Fusion? A relative of mine uses Kodi exclusively through a Raspberry Pi 3, and it is absolutely rock-solid. But I personally have two reservations with this setup:
1. While Kodi does provide excellent choice, (stunning, really) the overall user experience is often marginal compared to something like Netflix or Hulu+ on a Roku box. He experiences delays and buffering issues regularly (despite a solid, 60Mbps cable connection.) It's just not quite as "appliance-like" as Roku is.
2. I'm still not convinced of the legality of using Kodi with add-ons that provide current content for free. Isn't the whole infrastructure (especially add-ons like Fusion) dependent on an independent community to provide the links? Are aren't the links simply part of a torrent-style distributed network? I just have a hard time believing that the available content is in any way legally hosted.