There are a couple of factors that impressed me with OCZ's PC4400 memory. For one, I liked the use of copper heatspreaders. It is well known that DDR550 memory does get warm and using a heatspreader material with a higher heat conductivity rate just makes pure sense. It has been argued for some time whether heatspreaders are really necessary on memory today. For PC3200 memory, this may indeed be true, but for PC4400, it's mandatory. Kick in the fact that it looks great (see picture above), and you have a great combination of practicality and aesthetics which is sought after by enthusiasts today.