If you are wondering about the ARGtek...

[Ridebonfire]

My stock transmitter wouldn't get my P4 more than about 3500 feet (I live in the city). I bought wind surfers and I got to about 6800 feet but realllllly had to point that thing and constantly readjust. I did a lot of research between the ARGtek and dB mods and figured I would start with the ARGtek for the price (picked it up for $50 shipped on Amazon). Had my maiden voyage and got to about 9500 feet before my P4 maxed out (didn't know you could change that setting). So it definitely works and I didn't have a single video drop or flicker and bet I could have gone way farther as I still had more than half of the battery left. Obviously the dB mod works and gets you farther but I like the look of ARGtek, it's cheap, and I managed to save my stock wires and the antennas. Install took me about 20 minutes and was very easy - there is English videos on YouTube.