> do I really want to do this?
Well, it took me a while or so to decide whether to or not...
> What does "Russhify" mean?
Not sure - Probably allow it to show Russian chars if you add Russian books, but there's no effect if you stick to the normal English books/chars.
> Will displaying the clock use up the battery?
No, it only gets updated when you turn the page - it can be switched off too, if not wanted.
> Does the 505 operate just as fast or just as slow?
Exactly the same as far as I can tell.
> Will future updates by Sony be affected?
Would expect them to reset it, so you'll be left to wait for an updated image before you can get the 'improved' UI back.
> Is there a way to de-flash - return the old files?
I think the basic 'new_obj.img' in the flash kit is the closest to the old files, but I'm not sure if anyone's asked got (or asked for) the original image.
> What use is there for a 505 brick?
We thought igorsk had bricked his, but he managed to find what had changed from the 500 to the 505 and produce this flasher & get working again.