Help How to fix sluggish Galaxy S5

[Buyers_Remorse]

I just switched over yesterday from and LG G2 to a Samsung Galaxy S5 in the T-mobile store, since my G2 was having GPS and screen burn-in problems. I'm now regretting this because the S5 is somehow slower and more sluggish than the G2 despite having a faster processor, mostly due to TouchWiz.

In general, I've been able to overcome some of TouchWiz's problems by turning off animations, disabling S voice, uninstalling some bloatware, and using Google Now Launcher. I could live with the residual half-second difference in most operations, but three things are still bothering me:
1) The speed of the notification panel pull down is quite slow with the S5 but was lightning quick on the G2.
2) The S5 system e-mail app takes almost a second longer to load messages than the G2, which almost instantly
3) Ending phone calls takes a few seconds on the S5 whereas it was pretty instant with the G2.

I swore that I would never get another LG product after my problems with the G2 but I am seriously considering eating the $50 restocking fee and getting the G3 (or maybe an HTC One M8). Does anyone having any suggestions on fixing the above three problems that does not involve rooting the phone (trying not to void warranty for now...)

 

[Freebee271]

I switched to Nova Launcher (Prime) for Touch Wiz replacement.
Never used the pre-installed email app. (Gmail app in leiu).
Phone calls seem to end instantly on my S5 (at$t)

 

[Me_Droid_Freak]

I am not at all a fan of Samsung's samsucky interface. I'm convinced you could change Android versions and never know it because Samsung covers up all the curves and angles. Anyway, feelings aside, getting rid of TouchWiz is the only thing I could suggest, but that would involve rooting it.

A possible work around to the email situation is to use a different app than the system app. Gmail for instance.

(If you do change phones, htc's One M8 is totally awesome...)