Howdy all- I've been shopping around and have settled on purchasing a G5 2.0GHz MP. I'm trying to build a machine that's fast and reliable and also has some longevity, so I'm upgrading to a Radeon 9800 Pro SE (256) and a fast boot disk (WD Raptor 74GB). The question now is memory. The box will come with 1.5 GB (512MB Apple plus 1.0GB "free" from MacMall) and I want to get to at least 4GB. My questions: 1. Is it okay to mix and match RAM brands? I've heard that the G5's are more sensitive to differences in RAM and I'm wondering if I should junk the included memory and just buy 4 sets of 1GB modules all from the same source? 2. Any problems in mixing sizes (256MB, 512MB, 1GB)? 3. What has your experience been with brands in particular? I've always used Kingston to upgrade and have never had a problem, but in reading the Apple support forums, it seems like no manufacturer (Kingston, Crucial, others) are immune to problems. How about the GVP memory MacMall sells or the memory from OWC? These have great prices but I also wonder if you get what you pay for. The critical factors for me are performance and reliability. Although I want to avoid parting with more dollars than I need to, I'd rather invest some bucks up front to prevent flaky memory problems from happening down the road (I read some horror stories of RAM that passed hardware tests and "seemed fine" but caused problems later when getting stressed by huge Photoshop files). Any thoughts or suggestions would be appreciated.