Dave,
Its a point of diminishing returns, 4 gig of memory on this Core2 quad allow me to do just about anything I have ever needed and the 3 gig Core2 quad is no slouch in terms of speed. The i7 is marginally faster and the box has 8 gig for Win7 64 bit but the bulk of software that I own is 32 bit and it does not do anything much better on the i7 than on the Core2. The down side is I don't like the Win7 interface and while I found a set of stubs that allow the old NT4 Winfile to run on it, the fundamental interface is slow and designed for consumer idiots rather than experienced users. The up side of 64 bit Win7 is most things run fast on it, particularly internet related applications.