Pros It's a very quite DDR-3 system with 4 DIMM slots. It has just what I want with a decent ATI/AMD 4200 with HDMI. I've upgraded mine to 16 GB of DDR3 1600 Patriot Memory and and an SSD... it is fast!
Cons Some proprietary Dell headaches. If you want a new case, you will run into problems with startup messages and possibly crashes. The heatsink attachment to motherboard is proprietary and non-standard. Lack of drive bays... just two 5.25" and one 3.5".
Summary This is a nice system and with Dell they test everything for stability and always support it for at least a while. This includes the BIOS upgrade for 16 GB of RAM that I have installed in mine.UPDATE:
Updated on Sep 23, 2013
The motherboard would begin to not recognize my 16 GB of RAM. I tried going to 4 or 8 and it them completely turned into a dud and would not turn on.
I've since replaced it with an Asus M5A78L-M/USB3 and with a little tweaking on the motherboard headers from the Dell case have got it to work fully.