In my opinion, the good thing about Samsung tablets is that you pretty much get what you pay for and there's quite a lot of Roms made/ported for them. The Galaxy Note series tablets has better specs than the Galaxy Tab tablets. So if you want to use your tablet for more than a year without raging in frustration because the tablet can't cope with newer games, go with the Note series.
But the bad thing about Samsung tablets is that some, if not most of the newer Samsung Galaxy tablets have knox preinstalled in them that will break your device if you install custom Roms in them. There are ways to remove Knox but because of that the development of certain models are stalled and slow compared to other tablets from other brands.
Another thing is that, one model could have a lot of different version. An example, the Galaxy Note 8.0 might have a lot of custom Roms made for it but there's also a 3G , LTE and WiFi version and the most supported model is the 3G version and you bought an LTE version with little ROM support? Too bad for you then because you can't flash custom Roms made for one version with another version without having at least an annoying side effect.
Tl;Dr once you choose a particular model, go to that model's thread and see how much developer support it gets before buying it.
Sent from my GT-N7105 using xda app-developers app