I just want to see passion. The most vanilla set can be good if it's delivered with passion. Some shows of the US tour 2010 for example, they had the most bland setlists but they were delivered with a lot of passion and I still listen to them a lot.
The vocals - well they are what they are. But since their "return" I have rarely seen the band passionate on stage (minus Tico). During the 2016 promo shows I felt a bit of that hunger again - but ironically only when he was talking inbetween the songs. When I first saw them in 2003, his voice was (for that time frame) pretty strained already, but damn - there was so much hunger and excitement on stage, it made me fall in love with this band and their music.
Now they really seem like civil servants - doing their 9 to 5 job and then going home. Last summer I saw Kiss. Paul Stanley's voice is even more shot than Jon's - but there was still that excitement of performing to be seen, the commanding of the crowd, the joy of being up there on stage. If I'd only get that, I think I could leave happy next year. But at least get that back.