MountAsROM has absolutely no effect on anything and has nothing to do with the never-realized Ramdisk. That is, if someone states “with MountAsROM hacks, you can have the same speeds as with WM2003SE”, just don’t believe it.
These hacks can be found mostly in Chinese forums. On English forums/in my blog, they are posted by for example ‘liminwei’ ( see this post (05/31/06) and this thread).