Ya, customs can suck. Both times i have come to Canada for work i have not had any issues. They send me in for a second screening since i am carrying tools and what not but nothing serious, they just want to look at them to make sure there is nothing "illegal" in there. I am always tempted to make some smart ass remark but i am too scared of being taken to seriously.
Getting back into the US is easy, they just make sure you are not smuggling in any goods and they kick you out the door.