Hello!!!
Most often u can judge a little bit of the sups character by the way he corresponds to u via e-mail-Is he thoughful, is he friendly, is he concerned, is he prompt in replying to ur queries etc. Then next thing would be to find out by having a chat with him.... But these things would just give u a rough idea as to how he might be....I f u are really desperate u can hire some agency to spy on him...hehehe!!! just kidding!!
Herz wishing that u get a really gud sup!!
Cheers!