Similar - if I watch live tv its because I’m watching a sporting event - sometimes I watch NFL live…but being that these are 3hr long programs and the few second load time is not a big deal since I’m not channel surfing.
I don’t think I’ve channel surfed in over 10 years when I first cut the cord and bought the lifetime tivo - back when it was $300 for lifetime…still have that box and it’s working fine!! 
Now i notice that if i watched a live channel and switch to anoth er and then come back to the same channel, it loads much faster…why is that? Because of buffer? If that’s the case, there should be buffer for every channel doing work in the background to speed things up in case users want to watch live channels. Whatever it is, i find the system inadequate for instant live viewing.
plus, when watching sports you can do you own replays and “2 minute warnings” for bathroom breaks, I love my Tablo!
An already tuned in channel will load much faster, like 2 to 3 seconds, because it has already done the preprocessing required to display on your viewing device.
The preprocessing involves converting the live TV signal format to a format your viewing device, like a Roku, can use.
Sounds like you made your decision.
Good luck.
You can’t buffer all the channels, limited by the number of tuners. Only 2 channels can be buffered on a dual tuner.
Whatever it is, i find the system inadequate for instant live viewing.
Not surprising, because it’s not designed for that.
Perhaps a compromise feature can be that an alternate tuner (if available) starts buffering when a channel in the guide is simply highlighted. By the time a user hits the OK button to select the channel, that’s probably a couple of seconds of prerolling that could be queued already.
I use mine all the time for live tv. See the Tablo features this feature called “Guide”. It tell’s you what is currently airing on tv so you can decide what to watch without endlessly flipping the channel! Crazy right!