How big is the difference between a Small and a Medium? Sometimes I find that Medium is too loose for my liking, while other times it's fine (but it seems like only my older mediums fit me as I like for them to). But I don't want to order a small tee or small tees only to find that they are uncomfortably tight. I am relatively small chested but not ridiculously skinny.

And on an even more more selfish note, I would kill for some street team points right now. I cannot let this sale pass without buying any tees but having about $30 in my bank account is not helping! And Threadless's photo uploader hasn't worked for me since they changed the site around. :(

http://www.threadless.com?streetteam=Arise