I love mine. It's a great machine. Deep enough to be dangerous, good recovery speed, and multitones. Also, a TON of coil options. I like to run mine in the tone mode, because 7 tones gives you quite a bit of information, and also there's a bit of "bleed-through" with the discrimination circuit that drives me nuts. Running disc wide open in tone mode negates this.
I've found it's best to use a high-quality set of headphones with a limiter function, because the volume is directly connected to the sensitivity control, and thus, you can run high volume without deafening yourself. I run mine at near maximum sensitivity in tone mode to get weak-target volume out of it. I also NEVER use discrimination. In fact, I personally feel the audio provides such a wealth of target information, I have covered my screen with a Crown Royal bag because I consider the display to be a distraction for me. Although the machine is very chatty at high sensitivity, I feel it is the best way to get depth out of the M6, and I had no problems getting used to it.
I will also state that I am not an M6 "whisperer", and I am still learning new things about the machine every time I take it out. I'm just offering things I have discovered in my ownership thus far. There are many guys on here that could offer us both great advice on how to best use this machine!
Btw: 150 bucks is great deal.
