Oh yea, we used both SoftICE and Periscope. I loved the pushbutton to fire off an NMI directly on the ISA bus. It was sad when your device driver crashed but it was a fun experience to push that button.
I've used only few times back then, but it was impressive (previous experience was with Borland's / Turbo debuggers which was nice also, but Numega was just another class)