Without a doubt, when my XS was brand new and now that it is over 6 years old, FAST ON, with my maxed out settings is not good at all. I do get a lot of falsing, with the same settings I use with FAST OFF.
Maybe by backing down , way down my sensitivity, gain, limits, volume, headphone volume, hold my coil 6 inches off the ground, than maybe FAST will be OK. Yes, I am being a tad sarcastic.
I stated in a previous post the only time I THINK FAST worked to get me a coin that I would not have gotten without it was a one of the most horrible iron laden sites I ever hit. BUT, it is entirely possible I would have gotten the coin without FAST. What I did that day was lower my sensitivity from my normal 30-32 down to 15. I did get a nice 1800 Large Cent using FAST that day, but then again, from the same homestead, I got 3 other Large Cents with FAST OFF.
Again, I think the most important thing is to just go real, real slow in the heavy iron areas and the ole standard of different direction hunting.
My settings for almost 6 years have remained the same and my finds have not been that bad in that period.
Don in SJ XS - Dec 2000