This really tickles me. Let me explain this the dummies way. Take your amoled device and try to read an ebook or a webpage for a while. Then try current gen mobile phones with LCD display like:
1. N900
2. Wave II
3. Xperia X10
4. HD2/HD7
5. iphone 4
6. Optimus Black etc
and try to read same document or webpage. many (who are able to notice) notice that the text is much much smoother on LCD panels.
and btw, if you are talking about SuperAMOLED on SGS, it is even worse, thanks to it's inferior PenTile matrix. Oversaturated colors (some misunderstand this as being vibrant colors), just a bit washed out fonts. SA+ on SGSII gets much better but still, when it comes to reading, it's not match yet for LCD. It will take time for OLED to get to that level but right now, it is not.
The above observation is from this:
I am testing X7 with amoled display, I have N900 and there is X10 in my house. I have already tried friend's SGS, HD7, iPhone 4, N8 etc.
yes. it does. sometimes, a lot and sometimes, not much.