You're both right - MJ makes you far more cautious and analytical, but not necessarily more correct. AKA paranoid

Either way, the "impulse buy" reflex is significantly stronger with alcohol than MJ, according to myself and the anecdotes of most everyone I've talked to.

It really depends on what you're smoking. Sometimes my brain turns to mush for a couple hours and sometimes I come up with brilliant ideas I never would have thought of while sober. I credit it with helping to pull me out of depression by making me more appreciative of all the great things in my life, as well as helping me discover and explore my deepest passions. My life would be very different without it.