I have original quad and 4 tuner 4th gen. I like the 4yj gen better with the streaming channels the best.
I don’t own a 4th gen. Why? Because it doesn’t have any of the features I need at all.
Not saying the OG networked Tablos were perfect, but at least the ability to have Live TV or access to recordings anywhere was/is possible.
With that said, since the OG models are effectively “dead” as far as Tablo is concerned, I’m doing more with Plex DVR, which is OG Tablo++. Password controlled (truly watch/use from anywhere), commercial skip and removal, native format but with built-in transcoding based on endpoint, recording prioritization, EPG comes with Plex Pass, it’s both a DVR and general media server, ability to support 8+ tuners, edit: no stupid sync, etc.
If you have a Plex server already, I highly recommend it.
It’s a tough call. My legacy 2-tuner is used mainly so I can watch TV on my Windows PC, because I have two screens and am on it a lot. My 4th gen 2-tuner is used as my main device for my TV sets, as well as my Android phone.
My favorite features of the 4th gen are watching live sports in native MPEG2 It is an improvement over the legacy on 1080i channels. I also really like how quick the Android app loads (the legacy Android app takes forever to sync).
So overall, I use the 4th gen more, but I can’t get rid of my legacy anytime soon. If the Tablo folks can get a Windows app working (it may have the same MPEG2 issues like the AppleTv), I would go completely to it, and likely get an external hard drive. Right now I am fine with the built in storage.