When a new software release is made for an OS, all the developers would have done is test it on a very few devices within the developers and then roll it out to testers. And after analyzing the bugs identified from these testers, the developers sit on fixing it and finally come up with a release. Now would this release be bug-less? Absolutely not! Remember, its only been tested amongst a very few number of people and the rolling out happens to thousands residing in different parts of the world. If you think about it, what these updates are gonna deal with is a varied number of users, different carriers, sim make etc etc.
Take for example, for Indian users, the 4.4.2 update has been rolled out for quite a while. Lots of bugs were identified since then and the forum managers have been collecting data from the subscribers for quite a while now (Almost 4 months). Still the fix has not happened. And now 4.4.4 is out and issues persist.
I hvae been using 4.3, 4.4.2, then CM11, Mokee ROM etc etc, and now Im finally back to stock 4.3, coz thats the most stable version. So if you are someone who is interested in trying out new releases, please go ahead, but if you are someone who needs a stable ROM with no signal drop issues, please stick to 4.3.