Check the garage forum for more info, there were a couple of good posts there earlier this week. DBA make Tickford rotors by the way (except the high perofrmance ones) and they don't warp or shudder as easily as ford ones!
I can tell you guys that for everyday performance, you will not get extra braking power from the drilled DBA rotors. They are only superior if your brake temp increases to 600-700 C, which you should only see on a race track. My advice - get a set of slotted DBAs with Bendix Ultimate Pads (recommended by DBA themselves as well as me). These discs are just as good and cheaper because they cost less to make.
If you want to know the difference (and anyone please correct me or add to this if I make a mistake here), the drilled holes get rid of gases on the surface, allowing them to pass into the vents and extracted out of the disc. These gases are a result of extreme heat burning parts of the pad and disc (on a molecular level), that's why you don't really need them for everyday use. They are also noisier and chew through pads quicker.
The slots de-glaze the pad which provides provide a good "rough" friction surface on the pad face. The galzing occurs from s#it on the rotors and pads getting hot and melting a bit, which forms a kind of protective sealant over the pad and reduces braking efficiency as it is smoother than the pad face is normally. The slot scrapes this layer of gunk off the pad face, giving better friction and stopping power.
If you really want serious perofrmance, speak to CEBCO, but the cost is higher. They have a 330mm rotor which is oobviously better and they have 2 and 4 pot calipers. mmmmm.......
But remember no matter how obsene your brakes are, you can only stop as quickly as your tyres let you.