I didn't want to hijack the AppleTV thread but saw 2 questions about Tablo so I thought I would chime in. Also, since Tablo has an ATV4 app and the OP talked about lack of apps, I guess it is fitting.
I owned a Tablo 4-tuner for about 18 months, and generally speaking it worked pretty well. Honestly, I don't watch whole lot of OTA TV and rarely record. But when I did, the Tablo did its job. I don't recall ever having a missed program.
They released the ATV4 app a couple of months ago, and while a pretty basic app lacking full functionality of other Tablo apps, it was up to the task for a 1st version. Prior to the ATV4 app I would use my iPhone to start programs, then Airplay to get them to the TV.
In terms of complaints about Tablo, the biggest is that is is very very sluggish. There is about a 10 second buffering every time you change channels because of the methodology that Tablo uses to record. But even beyond that, the UI was generally sluggish overall. It is not for people that like to channel surf.
The ATV4 app was by far the best Tablo app that I used, as on the FireTV Stick and Roku Stick it was painful. Granted, they were both underpowered stick devices, not the more powerful boxes. The best experience is using Tablo via web browser where it is by far the most fluid.
When I did record, assuming a full program, playback was quick, way faster to load than live TV. However, trying to watch programs that were in process, before recording finished, was often troublesome. I eventually just gave up trying and wanted for things to completely finish recording before trying to playback.
On a scale of 1 to 10, I'd rate the Tablo about a 6. Conceptually it is fantastic, but there's a long way to go before it is a great experience.
Now, contrast that with another similar option, the HDHomeRun. I sold my Tablo and bought an HDHR about 3 weeks ago and to be honest much prefer it. Again, remember that I don't record much at all.
Tablo and HDHR have similarities, but also many differences. Most notably, the HDHR is a tuner only, whereas the Tablo is both a tuner and DVR device. Further, HDHR is available in multiple models that can be used for OTA/antenna or via cable TV. Tablo is strictly OTA. Finally, to record using HDHR you have to have separate hardware and software.
There is an excellent ATV4 app for HDHR devices called Channels that is for live TV only. It is super-fast and fluid and makes for channel surfing a breeze. Channels is working on a DVR solution that they expect to roll out in early 2017. It will require a running device (computer or NAS) to save recordings.
Plex will also allow for recording from the HDHR, but you need to upgrade to a PlexPass subscription. And again, you need a running device (computer or NAS) to save recordings.
SiliconDust, the maker of HDHRs, is also coming out with a DVR, but it is literally about a year late, so who knows if it will ever see the light of day (beyond its current pre-release state).
I would rate the HDHR + Channels app a solid 8. I just installed the Plex DVR and would give it a 6 (it is brand new, still in beta, and a lot of promise).
I know that is a lot of info but I hope it helps.
TL/DR: Tablo is OK. I personally prefer HDHomeRun + Channels + Plex. My opinion is based on using Tablo for ~18 months and HDHR for ~3 weeks.