[Nexus 4 Q&A, Help & Troubleshooting] kanwal236:
Not sure if this all has been addressed or not, but here is my 2 cents, considering I know quite a lot about the phones mentioned.

I'm currently using a Galaxy S right now, my dad has a T-Mobile Galaxy S2 (although the tmobile variant uses a very different cpu, more on that).

Your galaxy S2 looks much better than the GNexus because that phone, as well as my Galaxy S1, AND the galaxy s3 all use Pentile display; meaning they have 2 sub pixels for every one pixel compared to the galaxy s2, which has 12 sub pixels. However the two displays of the Gnexus and the S3 are Identical save for the screen size itself, it might perhaps be an illusion caused by the backgrounds and colors chosen by Samsung that makes you think the S3 display is better than the Gnexus. The S2 has the better display of all of these devices.

Yes the colors on Super Amoled are oversaturated, but like you, I actually prefer those colors, cause they look really amazing. The IPS display of the N7 is more accurate, and those whites are more true, not oversaturated. Cannot comment on the screenlift and light bleed though, that's quality control, I would not be a happy camper.

The speed of the devices and responsiveness..The Gnexus uses Tegra processor, it's crap, pure crap, that's why I didn't buy it, so I'm not surprised you felt lag on the device, even screen lag. Nexus 7 uses tegra 3 though, MUCH better, since it's quadcore, but, it's still no where near as good as Samsung's Exynos 4 quad or the Qualcomm S4 Pro (Krait SoC). Your S3 uses the Qualcomm Snapdragon S3 (Scorpion) SoC. The dualcore scorpion is a good chipset, has great cpu performance and decent gpu performance, there is no doubt about WHY your S3 performed better, because it simply had the better processor. I hope this is clear to you that in the US variants of the S3, Samsung used Qualcomm's processors NOT their own Exynos processors; the Note 2 has Exynos 4 Quad.

So in conclusion, the Nexus 4, seeing that it's using the quadcore version of the same processor in the S3 (which has dualcore), performance WILL be better than your S3, though not super noticeably as much because not many apps take advantage of quadcore vs dualcore. Ram is 2gb and seeing as it's made by samsung I'll wager it's the same as the one in the S3. Display technology is IPS LCD, if you love amoled's blacks like I do, you'll probably miss that, I know I will, but at least the display has more sub pixels than Amoled and is a lot sharper, see: http://www.youtube.com/watch?v=YF-Z3_f3WCE

I've done a lot of research on phones as they've come out to see if there's a good upgrade around for me, because I'm poor, I only upgrade every once in a while. Nexus 4 seems like a great upgrade option for me, unlike the S2, S3, Gnexus, (Note 2 was awesome, but too expensive at 379 on 2 year contract!). Only real negatives I've seen are:

No Sd slot (Dammit google, I want one!),

non removable battery, you can still replace it when it starts going bad in 2 years, this IS XDA.

No LTE, the necessity of which is negligible, unless you have crap home internet.

p.s. If your display has yellow, that's the glue that hasn't quite fully set in yet, it'll go away.