I bought the spypoint black flash a month ago, I am very happy with it up to this point. What pics I have gotten have been very good in the day and decent at night.
I have a few G4's. They work good. If you get one make sure that you check the firmware load and update it to the current version if there is an older version on your camera. Spypoint released new firmware updates to the G4 last month. Here's the link: