I don't run my Aug suppressed - but I have been really happy with it. I bought the NATO version as I don't mind using the charging handle and wanted the easier mag release.
A few things to note about the Aug is the trigger isn't as bad as they make it out to be. Now, that being said - it isn't great. There are a few aftermarket fixes. I bought a ratworx 20/20 sear but had issues with it (it is known some guns double with it - and mine does) so I ordered (and am waiting) on the lighter spring kit from Steyr-USA and will probably pick up an additional old trigger pack to try the sear again with.
GarandThumb's review on the Aug - he shoots it quite a bit suppressed and doesn't mention anything about any issues doing so. I generally find MAC is a bit of a drama queen and I am convinced he drums up 90% of his issues with guns for clickbait.
The big thing to consider when choosing what version Aug - is obviously the NATO or normal pattern. You will lose the bolt release on the NATO version and have to resort to the charging handle - however you do gain a mag release button in it's place (that is easier to use than the paddle IMO) in addition to the paddle on the bottom of the stock.There are two companies that make aftermarket mag paddles (Covus Defensio, which you can get from Steyr USA, and Manticore.) If you really want the ease of a bolt release then you have to go with the non-nato version. Steyr mags are cheap, and the magpuls are as well. If you pick the wrong version and regret it later - there isn't an easy/cheap way to swap as far as I know.
I have mine setup with a Vortex UH1 w/ flip up 3x magnifier and have been quite happy with the accuracy. It isn't a 1 MOA gun, but it seems to be about as accurate as any of my other 16" 223 semi-autos. At some point I will probably throw one of the LVPOs I have on it just to see exactly what it groups at 100. So far I have approx 1500 rounds through mine (I have had it two weeks) and it has been 100% reliable with both brass and steel case (minus the doubling caused by the aftermarket sear.)
I think my favorite part of the gun is obviously the looks, how compact it is - and how easy it is to disassemble. I also like the recoil impulse more than that of my ARs, Sig556s, etc. They were really thinking when they designed the Aug.
I haven't shot a Hellion yet - it was on my list of consideration, however after handling a couple it just couldn't get past how "busy" the gun is. There are adjustments and doo-dads everywhere and that was a turn-off for me.I like the Tavor - but I don't find it is comfortable as the Aug and I have a few buddies with them and they have some weird accuracy quirks (nothing debilitating, just some odd behaviors.)
Also, as an FYI - Atlantic Firearms has either version of the Aug on sale for 1630 + 30 shipping and they don't charge tax. That was by far the cheapest I have found them recently (and why I bought one.)