I dont remember too much about Pi Beta Phi's pref. I do remember that with Theta not only did i boo-hoo there as a PNM, but i continued to boo-hoo each time I did it on the other side. Two years ago I went back to my chapter to observe their preference ceremony as an advisor and I cried again. It brought back so many memories of me experiencing it as a PNM.
I've never heard of a preference party anywhere with any chapter though that was not emotional and as beautiful as can be (as it should be!).