The technology of slots and holes are viable for track and autocross environments, but much less so for street. Holes gain you less mass for quicker acceleration; holes and slots gain a little if you have more of an organic based friction material that will out gas at elevated temperatures. Both show a little improvement in reducing wet fade at low hydraulic pressures, but that advantage goes away as the pressure increases and the pads are able to squeeze and scrape water off the rotors surface. Holes, even those chamfered, have a propensity to develop cracks if the rotors temperature gets elevated in spirited driving.
The friction material compounds sold OE and mostly aftermarket for the DEW 98 platform are not organic, while some of the rear pads are more towards a low-metallic compound, such as the OE rear pads from Ferodo/Federal-Mogul. So there is little outgassing or the need for either slots or holes unless you are changing to a cheap compound or see extreme temperatures in autocross.
The iron used in the rotors is pretty standardized. The cost basis mostly comes in from the quality control of the casting and machining. Despite what many think of OE parts, you will not find a better QC or machined rotor then the OE rotors. The Motorcraft (aftermarket) rotors come close to OE standards, which are supplied to Ford by Federal-Mogul (Wagner). The Motorcraft standards are tighter then those sold as Wagner, although both are made at the same location in China. The OE rotors were a product out of TRW Brazil.
