[Aoife]

The assisted is an ok machine, and you do do work (assuming you do work) however the different mechanics mean that you still may not be able to do a pullup when you're no longer using the assisted.

At least incorporate other pullup training so that you slowly can do a full pullup on your own. Like... use the machine when you have a workout calling for "pullups" if you like, but on your own time training to do pullups do other exercises mentioned (except the pulldown... again, different motion. I can pull down more than my bodyweight yet can't do a pullup.)

Here's a good way to go about it:
Krista's Mistressing the pullup