I went through both (I quit halfway through formal, and was later invited back to informal) and I preferred informal out of the two. Formal is very fast paced, and you talk to so many girls at each house that you can barely remember who's who. I loved informal because I got to spend more time with the sisters and I had conversations about things other than just the sorority. I fell in love with the house and the sisters the more time I spent there. I would encourage you to go through formal recruitment to look at all the houses. If formal doesn't work out, definitely try informal. Good luck and have fun with it