Same here. It appears opinions are based on assumptions newer being better.
Google Play services from 5.x onward will not have better fuel consumption. Just watch the amount of wakelocks and location calls it produces. To me 4.x is the compromise at the moment, on KK and on 4.3.
The Google Play services stock version of 4.3 is actually 3.1.59, but it self-updates faster then I can say 1-2-3 when I access Play Store for the first time. Also, several 3. party apps have version checking and will refuse working at all with 3.1. Not that the functionality of these 3. party apps would be lost if they run with 3.1 or lower, but if version check does not find the latest version of Google Play services it will let the user not access the app.
BTW. There are a number of included original apps that self update soon, and then available RAM and internal space are getting a blow. Either phone makers need to address this by hardware solutions, or the devices should be fully functional and without crippled or old OEM versions which are just there to give users the impression that plenty resources are available.