I wish I could agree about the tension. The first elusive target was like you describe - studied the target for a long time, slowly planning how to strike, and then massive tension when it was time to act... but that was only because I had no idea that I could restart!
This second time, I knew that it was just a matter of getting alone with the target. Everything before that I could fuck up and then just restart.
After multiple restarts I knew how to poisen the wine and how to subdue the bodyguards without getting spotted, and thereby be completely alone with the target as he is puking his guts out
So for me the tension that I felt with the first elusive target experience was almost gone.
Also, I would like to see the elusive target have a more complex routine, and that there are some hidden ways you can get alone with target.. for instance like dressing up as the priest and having a confession time with the senator. Or 47 could "take over" as the mansion staff guy that is showing the senator around, leading him to a fourth location where a more satisfying/creative kill is possible without subduing/distracting the bodyguards. Something like that.
But hey, who knows, maybe there is and no-one how found it yet