You didn't mention what type of files you would be playing with respect to "video" and audio.
I'll be playing precompiled .MKV video files and I'm starting to think that PLEX is the better choice since I don't need any of the proprietary apps like Netflix or Hulu that require a Windows or OS X based system since those apps are on the Smart HUB so that lets me use Linux for the media server as it will only be .MKV video format, plus I was just looking at my friends media center and he's using an old HP DV2000 that had a faulty video card that we fixed and he accesses it on his MBP using Terminal and copies all his files to his HP DV2000 Ubuntu PLEX Server, which is connected to his Raspberry Pi and on his TV, works amazing too. it's extremely quick for what it is and I just happen to have a DV6000 and two DV9000's that have the same video problem so I might do that but instead of a Raspberry Pi I'll just use the Mac mini. He said the PLEX app for Samsung Smart HUB is pretty good but really slow which is why I think I'll use the Mac mini as the player unless there are other alternatives that the Mac mini would fit in better. Perhaps using the Mac mini as the server? would that help at all? I think these HP DV6000 and DV9000 are going to do the trick, he's using an old DV2000 and it works great, streams 1080p to his Nexus 7 no problem, starts up without any lag, but would the Mac mini be a better Ubuntu PLEX Server?
Better in what regard? How's the USB support currently working for you? Experiencing any lag, slowness, etc?
The USB Support is fine, it plays .MKV nicely however it takes for ever, closer to +1 minute(s) just to boot up the 4TB HDD so I'm looking for a type of "instant on" solution that I just leave on, it consumes low power and is ready to go when I am. I also don't like how it's organized, there is very very poor categories and on some files I have they are titled in series of 1 though 20's so it will count episode 1, then skip to 10, 11, and so on then after 19 it goes to 2, then skip to episode 20, then 21, 21, 23, 24, then 3, and 4, and so on, it's really quite annoying if I forget to rename the files because then I need to unhook it all, go back to my desk, rename all 20+ files to have a 0 infront of the single digits episodes and bring it back over to the TV and set it up again, wait about a minute for it to load then see if it works other wise I need to stop it after episode 1, go through the list of files till I find episode 2, play that one, then skip back after that one and select episode 3 and keep doing that until they're all in order, it's a pretty flawed system they have going on which is why I'm looking for an alternative of XBMC or PLEX but I'm thinking PLEX since it's more of a Media only player, less streaming add-on's for it like XBMC so it should be faster in theory.
However I think you already know this since you were running XBMC on your ATV1. I had one of those like 6 years ago, it was DOG SLOW running XBMC. It would stutter and lag trying to play high bit rate HD content. I couldn't imagine using one now!!
It actually runs better then the built in USB Support for the Smart TV, I was quite surprised at how well it's prevailed over the years. I do have CrystalBuntu installed though, not just XBMC on top of the stock OS. I remember running that and it was horrible, as soon as I formatted the ATV1 and installed linux to run XBMC it came alive, it works much much better like this. The main thing I like about it is how simple it is, I just open up CyberDuck, log in through SSH and copy over some files then watch them, quick and easy especially with my switch set up so everything is wired in for optimal transfer rates. I can't do that with my 4TB HDD, I literally need to go behind my tv and disconnect the AC cable, bring that, the USB cable, and the HDD to my desk, copy over some files then go back over to the TV and hook it all back up so I'm looking for something along the lines of what I had before with the Apple TV but up to date and faster while supporting high quality video.