My experimenting with the zombie senses started as a full gear in nw airfield, I stalked into the tents in daylight to get a feel for the sounds of the zombies and their vision and hearing. Then I capped one with a 9mm and watched them roll in from all around. ran just a bit and let them kill me. I think that one shot brought about 10 military zombies.
Respawned in SE electro beach, and worked the east side up to the power plant. Not that many zombies but I am not used to cities as much. It was starting to get dark and I was able to use the buildings and crouch to move pretty realistically through the area. I was able to hear the zombies enough to not agro any. The medical complex south of Topeka dam is challenging because of the limited access points. It was getting light by the time I got there and it had a full compliment of Zs. I was able to move though the complex including timing my crossing of the bridge a bit poorly and having to wait for a Z to turn his head to finish crossing. I found an Axe and killed my first Z. I stalked him in morning daylight but did agro him when he turned to me at the last minute. Seemed solid.
By the time I made it to Staroye it was full bright daylight. I kept going to evaluate the day light. Certainly more challenging coming in from the Big western Barn. Walking normally in the barn I aggroed a zombie outside the east wall. I like this, you have to walk slow when close and out of eyesight. It was a long process to work from the barn to the church to the clinic and then the police station in bright daylight with many many zombies, But I did it without agro, At the police station there was a persistant zombie at the road gate. She seemed not to be leaving and the longer you watch them the less likely they are to leave so I stalked and killed her.
I would say this build has a great balance of being able to avoid zombies if you are patient, but being totally vulnerable to players while you do so. The 1st player server is so empty that I am able to take an hour on a stalk.City is easier to move quickly through because of all the cover. Staroye was very challenging. Found a freaking FN and mag in the little crossroads military tent...Only one round though.
This balance of zombie perception seems far better to me. As a 7 year infantry recon scout.