I would most likely visit though that depends on whether I can fit it into my schedule. What happened was: this prof --a potential research advisor-- was ill during my original visit and cud not meet me. So, she has invited me ("as an additional visit for the program" to meet her and her students, and to show me around her lab. So, my second visit will be quite well-defined.
I personally think it is a good sign when the prof "courts" a student in this way...the prof must really be interested in the student as a potential member of his/her group, and is willing to put his/her best put forward to make it happen.
I will post my stats after I have joined a program. However, I will add a little something for now.