RAM quality:
RAM either performs at the rated speed without errors, or it has errors.
Once the RAM is inside your Mac, as long as it is error-free one brand will be equivalent to the next.
So the question really is: what is the chance that a particular brand of RAM will work without errors, first try.
Some configurations of PC3200 modules do not work in Macs. Apple does not say why or why not. Some manufacturers test every module before they are sold, which will mean a failure rate of below 1%, while some do only spot-testing, which can lead to as many as 5% bad modules, which costs you time and hassle returning it.
What you are paying for in brand name is
1) The company's reputation for testing and delivering working modules
2) The company's assurance that their modules work on Macs
3) The warranty coverage - what happens if it doesn't work out of the box, what happens if it fails in 2 years? Some companies only guarantee the RAM if it was used in the model of machine it was sold for.
Re: the other thread on Dell RAM; Kingston has a good reputation for testing (1). The Dell-sold Kingston RAM will absolutely not have a Mac compatibility assurance (2) and you will have to verify the warranty (3)
Geil is a new brand, so (1) is unknown. You will have to check yourself for (2) and (3)
Thanks
Trevor
CanadaRAM.com