Well, I'm pretty biased toward non-staggared on the e36, but I'll explain why.
A staggared setup will promote understeer, which is something that our cars already do stock, why make it worse. A little understeer is safe for the street. Too much understeer will just make your car plow into corners when pushed. It is better to have a street car with tendancy to understeer (plow) then to oversteer (drift/spin out), for performance reasons I'd try to dial out as much understeer as possible making the car more neutral.
Also, maybe it's just me, but I like having the option of rotating my tires. The rears are wearing faster then the fronts, move them to the front. Simple.
Unless your car is making like 350hp, or you've managed to mount the engine in the trunk, go non-staggared.
Both will be ok, neither will kill your or make your car drive worse in an everyday situation. If it's looks you want, staggared does look cool.
"Driving is like a narcotic, an addiction that can take over lives. It ruins people, breaks families apart, and even kills. Itís habit that needs to be fueled. Time, money, rationality, sweat, knuckle skin, and anyone who disapproves are of little importance to a driver, and are often overlooked. Hi, Iím Nelson, and Iím a drivaholic."