I recently got the GC500. I ordered the one from MFK with their sounds and the Icotech sounds, so it came with 35 sounds or so preloaded into the caller.. The sound quality is very good, although when I pick a sound I hear a slight noise coming from the speaker, like it is loading, I don't think it is enough to spook an animal and I don't think it has so far. I loaded my Randy Anderson MP3 calls and my JS calls to the unit, it was very easy to use, it is the same as the FoxPro spitfire to load sounds. I did try to load some FoxPro sounds on it and it didn't even recognize them on the remote.
I was a little concerned about the size of the text on the remote so I renamed all of the calls using CAPITAL letters and it helps some. IMO the remote could be improved. the light only stays on for a couple of seconds and then shuts off, I wish it stayed on the whole time.. the display could be bigger even with all capital letters they are tough to read sometimes.
Over all the call is a good one, and for the money probably the best buy of all the calls out there.. ICOTEC would benefit from making more calls available. Once they do and if they make improvements to the remote they are going to be tough to beat.