x800 pro to XT Hard mod

Guys, I have been thinking about doing this mod for some time now. I
currently own a Sapphire x800 pro. It has a blue board which is different to
what alot of the sapphire boards are, and in particular, most of the people
who have done the hard mod have had a red board.

I am in Australia.

My card currently oc's to 515 Core / 540 Mem. It's pretty good on stock
cooling, and I live in a hot area which doesn't help.

I thought about buying one of the vivo edition cards and just doing the bios
flash, but alot of those cards reportedly fail to go past 500/500 mhz I
wonder what the comparison is between an extra 50 mhz clock speeds compared
to an extra 4 pipes. I don't want to spend all that money to find that the
card can only hit 500mhz when I already run at close to xt PE speeds.

So anyway, I want to know has anyone had any luck with this mod with a the
blue board? I know the success rate for this mod is not that great. but I
have also seen some of the attempts and my goodness, they really have
butchered the whole job. Also I have not heard of attempting the hard mod
having any negative affects on the card, it either works or it doesn't. so
as a calculated risk I thought I might give it a go.

any experience with this guys? please share...