Rs4 calipers and 365x34mm discs - whose done it?

[Cornershop]

As above folks,

Has anyone done this conversion to a FL S8 currently fitted with Brembo's?

Don't need an upgrade, just weighing it up as I need to refurb my existing calipers

Aside from cost, is their any reason why I shouldn't do this? Happy with current brake performance so this would largely be form/bling over function

I was thinking of using rS4 calipers with w12 Phaeton discs which are much cheaper - would these or rs4 discs be a straight swap?

Do you need adaptors and/or hoses ?

Is there a weight gain in using RS4 calipers?

Does the brake bias change with rs4 front calipers alone? Would I need to upgrade the rears to reset the bias?

I see urquattro.net via eBay has a kit for the D2 that uses rs6 calipers and what looks to be phaeton discs for £1600- I think this could be done slightly cheaper as they charge £500 for the genuine VW phaeton discs alone.

http://m.ebay.de/itm/380328707729

Apologies for all the questions, just trying to see if it's a bolt on upgrade and if so, what are the downsides (if any, apart from cost).