Hi Mike
Yeah M16 is one of my favorites too.
All though the field of view is small for the asi120mm m16 makes a nice target.
I use firecapture for my pix and it works great even though i dont have a USB 3 port on my old laptop it handles it ok.
I have been doing all my images using FIT Format and stacking with Deep sky Stacker using default settings.
Deep sky stacker is a free program you can download from here
: http://deepskystacker.free.fr/english/index.html