I have used the hints and answers quite a bit, mostly for the actual STEP questions, once for the warm down as well.
One time I had to look up some stuff for the warm up, but this was me not knowing the standard trig things off by heart, which I admittedly should.
After using the hints, I try to understand why the answers are what they are. My thread of assignment two shows that. Moreover, if I have a lot of trouble on one assignment, I plan to finish the foundation course and then go back to do that assignment again, so I know I can do it.