you can flash most any rom with S-On, S-On is not the issue
ok, well I used to think that also but obviously you have not read the guide yet.
It shows many things. One of which is that you need to look for roms that are compatible with the firmware on your phone. If you do not know what the version of firmware is that you are using, the guide tells you what to do to find out. Also when you flash a rom from a zip file is does not overwrite the boot.img that is currently there you need to do that after you flash the rom.
It is truly awesome. I was struggling for about a month till I found it and now I love the custom rom I use which is Elegancia_Sense 3.6 Pure STOCK LOOKING, by the way.
Read the guide and see the light. lol