If was at home or smoking by my self and had to choose between the two it'd be a joint because when by my self there is no need to roll a blunt because there wont be a lot of people smokin and I don't like the fact it's tobacco. If I was with people it'd be blunt because they last longer, you don't have to constantly light it and you can keep passing it around.

edit: and no, a blunt wont help you relax. If nicotine does it'll only be for like 10 mins or so. After that you'll still have a panic attack if you're prone to it. I know I had a few panic attacks on blunts lol.