Worth noting the the M1144 / DS2550 etc. etc. are all for track use and are illegal on the street, if that worries you.
You can get the standard pads for about £55 delivered from Euro Car parts iirc. I think the most notable difference is a good fluid change, at least to pedal feel.
Euro car parts had a discount weekend on last weekend, I picked up a set of genuine Pagid pads for £25 - mine are same size as GTI brakes. Shame the sale is over
Still 25% off full price atm, not sure if that makes the Pagid £25...
Re: Pad usage, daft really, but here's a snippet from another forum:
ECE Regulation 90 (R90)
European legislation came into effect September 1999 titled ECE R90 that stipulates that all brake pads sold for use on vehicles manufactured after this date must be tested and comply to R90 standards.
This test which involves taking each homologated vehicle used on the public roads within Europe and comparing the front and rear brake performance with the original parts to those of aftermarket offerings, has closed the door to cheap and nasty imported brake pads. The test includes cold and hot brake friction analysis, and if a part has been approved to R90, it can be safely assumed that the product is equal to or better than original equipment product. The brake pads are then marked with an R90 code number and a country code in a circle such as E1 for Germany or E11 for UK which signifies where the testing has been done.
EBC Brakes does all of its testing at the VCA (Vehicle Certification Agency) test facilities at MIRA in the UK. 'MIRA' is the Motor Industries Research Association who have a high speed test track for conducting these tests, which EBC Brakes uses on a regular basis.
Factory approval is part of the R90 process which involves engineers inspecting and accrediting the factory manufacturing the product before approval is given.