I have dealt business with them quite a few times. Everything went smooth
Pretty much their installer is really a frontend for dosbox. So it installs it for you and should you want to move the full installed game you can go to your c drive/program files find the GOG folder and take the game from there and throw it wherever you want (like in actual dosbox with a slew of other games)
most of all games from them work fine. Vampire the redemption had some minor issues that they were able to fix (I think). And if you want be sure about a games compatibility, check their forums-
"What motivated him to throw a puppy at the Hells Angels is currently unclear,"
Starroid Raiders Dagon wrote "No Dime Store Monster left behind"