KODI is the new name for xbmc. Channel quality really depends on what you want to watch. My antenna picks up the broadcast channels in higher quality than DTV because the signal is uncompressed. Within Kodi we watch any tv series in hd quality but EVERY episode is available. I watched this weeks GOT episode at 10pm so the stream was up and available fast. If you add Stalker IPTV you can get every premium channel live as well but the quality does vary. HBOs ESPNs are good, NFLN isnt.
FYI, I plan to pay the $120 to NFL.COM to live stream games this year and use my VPN to login through a country outside the US. This method gets you every game even those broadcast on primetime.
The thing to remember is that this method isn't as user friendly as DTV. There is a learning curve and even then its clunky for live tv . However if you want access to every movie and tv show ever made then this is the way to go IMO.