I second that the emulation of some games is really bad, mostly when it comes to sound. In terms of lag and such things it doesn’t ruin my game play since I’m almost 40 and don’t have the same reactions as 30 years ago anyway

Fortunately those are not my favorites anyway (or I have them in better versions at other cabinets). But yes, if you select one game you will not see any menu at all. And it boots really fast as well.
As a cheap alternative to original game boards it is OK. Not perfect, but most people couldn’t tell the difference. Let’s face it, how many of your friends have played Donkey Kong recently on an original cabinet? =)