The 660s model I bought is my first new Dell computer in 8 years. I decided on this model for it's price & midrange technology. It's not the fastest model to choose from, but it's no slouch either. It runs pretty quietly & doesn't take up a lot of space, which is nice, since my old computer had a loud fan & took up a ton of space. There are plenty of USB ports, including two USB 3.0 ports, so I don't have any problems connecting peripherals.
I did run into a couple problems, though: 1) there was a registry issue I had to get fixed to get the CDROM to operate 2) I've had a few random error screens surface & had to reboot from a recovery drive a couple times.
Beyond those annoyances it usually runs quite well. For the performance & price, I'd recommend giving this system a look if you don't have a lot to spend and need a simple computer. If you have a larger budget, & need something a little more sophisticated, I'd go with a different model.