As long as your the games you expect stays in 90s, the 2d era then this machine is pretty good in emulating them, but year 2000s and beyond becomes difficult for this machine to handle, it lags and buggy.
Words of advice though, if you're going to buy this machine, make sure you don't update to the latest firmware 5.71. As it breaks coinopsx and onesauce. Making it impossible for you to add games anymore. So until CoinOpsX and OneSauce community fix the problem, don't update to 5.71. Recent cabs comes with firmware 5.70 and it might ask you if you want to update to 5.71, the first time you connect to internet. So make sure you pay attention while you setup the machine so that you don't accidentaly update it. Seriously, you've been warned. (Atgames did say that the update is optional, so you don't really need that update.)
Another thing, you might find the buttons scrambled and wrong except for the joystick, so it might bother you if the game you used to play has wrong controls (most noticable in fighting games), remapping the buttons might be required d in order to correct them, which is one of the reason why I started this thread, to ask anyone if they have mapping files that they can share with me (.rmp). So that I won't have to remap every single game. But then this issue is pretty common in emulator and mame machine.
Also this machine (atgames legends ultimate) is not just the only home arcade that you can purchase in retail. There's also Arcade1up, MVSX etc.. but of all home arcade out there, while this is certainly probably the priciest, this is definitely the closest to the size of the commercial arcade which is 70" tall while this machine is 66" tall. And also gives you a bang for your bucks. This one has 300 preloaded licensed games and can easily be expanded by plugging a usb with CoinOpsX, Awesome Sauce or Rcade in it, whichever of those three frontend you prefer.
I'm not a endorser of this product though I'm just saying what you might need to know and expect.
Also back to topic, If anyone have mapping files for Awesome Sauce and willing to share with me, please post here or pm me.