MaShaaAllah
But full sized headphones are nearly useless with a phone because of higher impedance. Thats where in-ear headphones come in because they are specifically designed to work with portable prodcuts too, hence have lower impedance, greater flexibility and equally impressive quality. But are expensive as hell.
I agree with the Stock Samsung handsfree. Certainly one of the best "stock" handsfree. But trust me, its no different than a Rs.450/500 headphones from A4Tech. (I have used the MK650 having 10mm neodymiums, the sound quality was amazing for the price i paid for it, and i would rate them equal with a stock handsfree. However, they weren't as reliable, couldn't go for more than 7-8 months, then the wire near the 3.5mm jack broke from inside, rendering it irreparable)
4S' quality is on part with Galaxy Nexus. Kinda hard to accept but thats the truth. You wont feel any decrease in quality, unless you compare it with a Wolfson DAC having Voodoo Sound mod.