I use my E6700 in a Windows 7 x64 build, used by my partner for general surfing and music, playing DVDs, and the occasional photo-editing (Lightroom 3). I have had no complaints regarding performance.
I built this computer with old LGA775 components (motherboard, 4GB memory), and a DirectX 9 gaming graphics card. As all the components other than the CPU were cast-offs, this was a very cheap build. This is probably the selling point of the E6700 - it is the cheapest CPU you can add to an old LGA775 motherboard to knock something up that will run Windows 7 x64 quickly and without needing a cheeky overclock.
The only downside is that the E6700 doesn't seem to be that overclockable unless you increase the core voltage (which makes the CPU run hot), but at stock it is plenty fast and quiet enough for what I need!
Even for high end games, it is worth noting that almost all of them are still only optimised for dual cores (for example, Skyrim and Shogun 2, two big 2011 games, are documented as being optimised for dual core), and unless you are playing something really cutting edge such as Crysis 2, a fast LGA dual core is still indistinguishable from a slower LGA quad.