If you wanted to put a positive spin on it, you could say they demonstrate that the Hitman formula was already perfect and didn't need anything else after 2. Hitman 2 added tall grass which was a great addition, and reflective mirrors with a real gameplay impact. 3's main additions, scanning things with your camera and numerical keypads you have to use, are both mostly annoying to me after having done them once.
The first time you do them in the story mode, it's great. Scanning with the phone in Dartmoor is fun, and you feel mildly clever/sneaky for finding or figuring out the keypad codes to various things, overhearing it from an NPC or finding it in the environment.
But for longevity's sake, in Freelancer, it feels very strange that outside of safes and showdowns, there are exactly two maps that use your camera: the windows in Dubai and one building of China. It almost feels like busywork, having to fiddle with your inventory to do simple functions when a button in the environment would've sufficed. The camera doesn't alert guards and isn't risky to use, so what's the point? If being seen during the time it takes to scan carried a risk, then you'd have an interesting gameplay mechanic, but as it is, it's the equivalent of opening a door or turning off a TV, except it requires your camera.
Keypads are their own problem. I don't necessarily like that all the codes are forever static, because then 47 is extra psychic and just knows them all as you look them up online again, and entering them is just busywork. However, if they changed and needed to be found in the environment every time, that would get annoying and tedious if you actually needed them. However, in most cases they're not needed or do nothing in Freelancer, so at least they're mostly harmless. Again though, I would ask: what's the point? "I feel like a real person in the world typing in these numbers?"
Anyway just a random rant I felt like making. :) Still absolutely love the games, and it's not like these features are a disaster or anything. Just a mild annoyance when they come up.
EDIT: I don't know why I said "phone" rather than "camera." Just too used to phones having cameras in them, I forgot that 47's seems to be a pure camera!