Just my 2 cents... I used Dolphin Bar very little. I wanted it for arcade gun games but it didn't work well being close on a smaller screen. It does work great for Wii games and OK for arcade games if you want to stand back 5+ feet which isn't practical for a cabinet but fine if you're using a large TV.
If you think about it, this device is really made to emulate Wii on a large TV, which it does well for $20.
If you want to shoot guns at a screen smaller than 30" plan to stand back too far from the cabinet to see the details of the games.