I'm running it just fine here at work. Mind you, I'm using it in 64-bit, with a Q9550 cpu, and 8GB of speedy ram.
Most people think it's a memory hog, but in reality, it's using the memory a lot more efficiently than WinXP. It's mindset is that unused ram is a waste of potential speed/space, so it uses it more. Most people go wrong and start complaining about it when they upgrade the software, but neglect to upgrade the hardware, then don't understand why it's slower.