Android 5.x Issues Gone After Wipe?

I recently procured a Samsung Galaxy S5 to replace my S3 and man was that an upgrade; it was fast as lightning compared to my clunky S3 that seemed to trip over itself.  The S5 came with version 4.x installed, so I ran updates to get everything ready.  I realized that after the upgrade to 5.0, the entire phone became insanely sluggish, as in worse than my S3.  I had read about this a bit prior to deciding on the S5*, so I looked up more on this and found the scenario to be true.

Terribly annoyed, I decided I would just perform a wipe and reset everything to factory default, crossing my fingers that I could revert to 4.4 by doing that.  As it turns out, a factory reset only wipes the user data and has no effect on the OS version.  If you want to do that, it’s a pretty intensive task that I would rather not have to deal with.  I decided to just go ahead and run with restoring my phone with everything I had backed up until I could plan out everything.

What I’ve found, however, is pretty crazy.  After performing the wipe and still having 5.1 installed as the OS, I’m finding that the phone is running better than before.  Keep in mind that I only had this phone for about 5 days before I performed the wipe, so it’s not like I had a year-old phone that had enough gunk installed all over the place.  Also keep in mind that I’ve only just got everything all set up how I like it again, so maybe this will all change after a few days.

Another thing that I’ve now noticed is that the battery seems to be operating at a normal level.  Before, the battery was being eaten up like a Gamorrean by a rancor.  Since the wipe after the upgrade, the battery lasts so much longers.

Regardless, I’m pretty shocked by this.  I don’t have a bunch of phones to test this on, but I’m wondering if after upgrading Android from 4.x to 5.0 you then wipe to factory defaults and then set up the phone with all apps and settings, does it run as it should?  Is there something wrong with how the upgrade process performs that would cause the OS to degrade?

If anyone out there can confirm this, that would be something worth sharing with the Android and Samsung community.

*I went for the S5 because I don’t need the latest and greatest phone out there.  I tend to get a model or two below the newest phones, mostly due to the crazy price difference between the two.