I have the 900 up and running! I have another post going that I don't like the ML 85 headphones. Playing with it a bit in the house doesn't do it justice. Coming from the 600,I find the navigation pretty easy. Going thru the tones I prefer at this time 5 tones. The Dp and At doesn't do it for me. It was strange to see a red back light and I never tried the flash light or the vibration handle. I think there will be issues coming with the cam lock system wearing out. I do like the fact that it can be made much shorter to save room while traveling. The first time I cant get outside I will probably stick to a factory program such as Park 1 with the exception of threshold and sensitivity settings. Any tips from you fellas will be greatly appreciated!! Thanks and HH! Ted