Update: You can check how to install CM12.1 Android 5.1 Lollipop OS on the Galaxy S5 by checking the step by step guide from here.
If you are planning in experiencing something different on your Samsung Galaxy S5, then I have some good news for you. Those of xda-developers just released a new custom ROM based on Android 5.1 Lollipop OS for your device. I am talking about the new CyanogenMoud built – CM 12.1 custom ROM, which is now available in an unofficial matter, for your Galaxy S5.
Therefore, you can anytime choose to download the firmware file (you can get the CM12.1 platform from this page) and to flash the ROM on your Galaxy S5 without facing any other problems. The update process will imply in replacing the stock Android OS that powers your smartphone with the new Android 5.1 Lollipop featured CM 12.1 software. The flashing operation can be applied only in certain conditions, so first you will have to root your phone and to install a custom recovery image on your device – if you are new to this type of update procedure, stay close as we will develop a dedicated step by step guide in which you will find all the details needed.
As for the CM 12.1 firmware you need to know that even though we are talking about an unofficial release of CyanogenMod, the update is stable enough for a daily use. In fact, the users who have already tested the Android 5.1 Lollipop OS on the Galaxy S5 reported that there aren’t any software related problems issued so far. So, you can safely update your S5 with the CM12.1 firmware as long as you are willing to complete an unofficial update operation – the warranty of your device will get void.
So, there you have it; Android 5.1 Lollipop OS is available for your Samsung Galaxy S5 in form of CM 12.1 custom ROM firmware. So, what do you say, are you ready to try it out, or you rather stick to stock Android OS?