Top 2 or 3?
How many hands they play ( loose,tight,nit)
If they are agressive with big hands or like to play them slow.
What hands they go all-in with (adding the street (pre-flop,flop,turn,river) and board texture (flush or straight draws present, paired boards)).
Last one can make or save you lots of money.
Anytime I see their hole cards I like to replay the hand and see how they bet/called/raised and how many streets they bet with what kind of hand. Gives lots of info.