My system is a micro. No problems here.
Right now, all of my PCI slots are open. I removed the modem, well, I had a reason at the time, but I forget. My graphics card is AGP. I am using onboard sound. So I have three empty PCIs.
Using a micro is just up to personal choice.
Oh, and Nukem, there's no way you could put an ATX board in my case, as it is a micro case as well. Besides, the smaller cases are really cool.
My Rig: SABLE
Antec 300 Illusion / Antec EarthWatts EA650 650W / EVGA GTX 760 2GB
AMD FX 8320 x8 Black Edition / Gelid Tranquillo / MSI 970A-G43
Sandisk Ultra Plus 128GB / Samsung 840 120GB / WD Black 750GB / WD Green 1TB / WD Red 3TB
G.SKILL Ripjaws 2x2GB DDR3 1600 - Crucial Ballistix Tracer 2x2GB DDR3 1600
Win7 Ult 64-bit - Func MS3 Mouse - CM Storm QuickFire Rapid Mech Keyboard
R.I.P. Danny L. Trotter
... 14 Nov 1945 - 4 Sept 2009