I was talking to Cain at TOTH earlier this year about brake pads, I have a set of EBC pads in my car and although they are ok, I asked Cain if there was anything better out there.
Without hesitation he recommended Mintex 1166, and so I think I'll give them a try. Bit of a price difference though: EBC Greenstuff are around £30 a set, Mintex 1166 are £175!

According to Demon Tweeks:
M1166
Manufactured to work from cold and keep on working until hot, while holding its friction level, the M1166 compound has been designed to provide consistent braking performance. With an optimum working temperature between 200°C and 400°C, this compound works well in long distance events where the demands on the braking system do not reach high temperatures. Positive pressure modulation and stable braking performance make this compound suitable for saloon car, single seater and sportscar use.
Key Points:
• High Performance from Cold
• Positive Pressure Modulation
• Flat Friction Curve Across the Temperature Range
• Average Friction Coefficient of 0.45
• Suitable For Medium to Long Distance Use