I've got the Blue Elf 309 V.2 and I'm really happy with it. I haven't played the King of Dragons so I couldn't be of any specific help on that one. The audio is kinda scratchy on some games but other than that it's awsome. The menu works great, though you can't set up all the dip switch settings like you can in mame, like no. of lives and difficulty and etc. You can set the no. of lives and difficulty on some, but not all games.