Normally I'd say that for a desktop, if you know what your requirements are, then go and get a custom job from somewhere like QuietPC (who were pretty helpful in making sure my spec was sane). Because off-the-shelf machines are unlikely to have a CPU/GPU suitable for anything other than office work or high-end gaming, and they never come with enough memory. But if you've got the memory going spare and know it will fit the Dell, that doesn't look like a bad choice.