Re: When you can
I wish people would stop perpetuating the lie that MythTV and Kodi are the same - and in particular that Kodi is a replacement for MythTV. MythTV is so much more than what Kodi does - and the "lounge TV" part is just a tiny bit.
In fact, you can (AIUI) use Kodi to watch recordings made ona MythTV system - but using an inferior experience that loses several key (and very useful) features in the native MythTV frontend.
And for good measure, there are people running the native MythTV frontend on the Pi - though I gather there are still some wrinkles to iron out.