The 4mp is a big deal if you use cam scanner app a lot.
Scanning quality will reduce. More mp the better, since can crop.

I'm using Samsung phone too. Touch wiz doesn't look nice if you're long term holo theme user.
Bt like all theme, eventually will get bored, change to tw once a while quite refreshing also.
There are aosp themes available if u know how to root. Some custom roms even have aosp themed by default.
Or there is always aosp roms like cm,aokp,pa.

S4 no lte?
S4 have snapdragon and exynos version.
In gsm arena snapdragon one say got lte while exynos one market dependent.
Why malaysia s4 no lte? Frequency not match?

You are right about the touch wiz gallery.
iPhone 4 single core also can view photos very quick, and can scroll very fast.

Touch wiz gallery is very slow, even on s3.
Sony gallery is even slower when I check on Xperia s.
There's always delay when wana scroll through the pis quickly.

When using aosp gallery, it's good in terms of speed, but I notice pics will appear slightly out of focus at first, and takes half a second to be clear. Kinda weird.

I notice the short blur in most gallery app when viewing pics from the TV via hdmi
The short delay for the pic to load to full clarity is very obvious. Most likely wont notice the small lag for the pic to be clear on the phone screen itself.

The best/fastest gallery app is camera jb+
It comes with its own gallery that looks exactly same like stock gallery, but no delay when loading pis.
Very very fast.

when user have s3 and dont plan to buy s4,
they'll say "no big difference, not worth upgrading"

when user bought s4
they'll say "wow big improvement! worth the upgrade"

lol....