Hi Splais,

Yes, I have used them and I'm using two now in my DP Extra. A regulated one on the ignition(I'm using 6v Duralites) and an unregulated one on the receiver. They are very good quality and work perfectly. The flag mechanism is unique, and looks cool when the flags are in. Functionally it is a bit of a pain to keep track of the pins when out, but that's only when you're flying, so you're not going to lose them, you just need someplace you put them each time so you can get to them easily at the end of the flight.

I would not hesitate to recommend them.