I have the 12-14 upgrade on my 75, on first startup the machine ran completely erratic, after two or three more startups it seemed to be totally screwed up. I made a video of how it was acting so I could send it to the Fisher technicians which was a good thing this way they can see it firsthand. The next morning I decided to go to a local site and try the machine out, forgot to mention adjusting sensitivity did nothing to clear the noise and chatter. At the site and turn the machine on and it did not do what it did on the video it was a little bit noisy but bearable and brought it brought the sensitivity down to 40 with no avail the chirping still air but it was usable. I tried all the mall modes that the upgrade had and ironically I found no depth loss, actually I was pretty surprised at the depth on the FA mode, two coins in one whole wheat Penny and a 43 Merc dime, the penny was about 8 inches the dime was underneath it close to nine,switched over metal mode, and she was running pretty stable can say I had a noisy experience went back over to boost same situation airborne and 99 quiet as a church mouse seems to be a problem in my FA mode. Contacted Juan at the Fisher upgrade section and emailed him the video, waited a day to hear back from him to no avail, so I called on the phone he got the video, him and a couple of technicians viewed the video and immediately sent me a return tag to have it repaired. I asked him if the upgrade section was to be repairing my machine he said no the video and my machine was going to engineers section so I think that's a good think as he said they wanted to try and see if it was somewhat the software. For those who have died 11-14 upgrade I had asked him if there was a definite depth loss problem and he said not anymore the earlier ones had a problem it was a software problem and they were recalling those machines to I guess reprogram, but don't quote me but I'm pretty sure that's what he told me. And this phone call was as of two days ago. I might suggest calling and asking for the F 75 upgrade person which is Juan and tell them about your problems and is see earlier upgrade. I hope this information helps somebody out.