Modders don't want to buy a complete power supply to test out Slims. Instead of having 2 PHAT power supplies, just just your normal power supply and then plug in the adapter when you want to test out a slim. Cheaper, cleaner, and easier.
You should replace your laser lens if your system has the following problems:
Cost effective NAND reader / programmer to complete the GliGli Hack.
It features a PIC18F2455 microcontroller for stable and quick reading/writing of all NAND models available on the different XBOX360 models.
The Matrix NAND programmer is also fully compatible with NANDPRO 2.0e and several other third party programming tools.