Had my spark for almost a month. 1700 miles on it. (150 mile round trip commute). Spark is my first ev, so I can't compare to others but I can say:
Range: very happy, to work at 65 mph with a 5 mph tail wind I go 75 miles with 20 miles left of range. Home at 62 to 65 and 5 mph head wind I go 75 miles with 8 to 10 miles left.
Noise: low speed, awesome. I love how silent this car is, and what little noises it does make are so alien to a car, like little electric motors and the just audible whine of the electric motor as I back out of the garage. I often mute the radio just to hear my futuristic space ship sounding car hum around. Freeway speed is as noisy as any subcompact, it's not a luxury car after all. No squeeks or rattles so far.
Stereo: meh. Quality is fair. At least it has speed adaptive volume though, and can play iPod, Pandora, and aux in for anything else. Also can play videos from a smart phone, if your not driving, like sitting and charging.
Worst thing: climate controls, they are confusing at best, and the efficiency meter makes them down right panick inducing. With the fan on 3 and temp at 78 to get the cabin warmed up for a minute, I'm at 100%! Wtf does that mean! Am I about to suck 75 miles of range off the battery!? I'll just use the seat heaters.
Runner up worst thing: infotainment controls in general. Getting to any specific screen, radio, tone, climate, settings takes at least 2 clicks of the sometimes unresponsive touch screen, and usually 3 or 4. The exception is the electrical info, by hitting the "leaf" button. (They should have made it a "spark" or at least a lightning bolt.)
Runner up best thing: performance. This car is so quick and nimble. My previous cars were a 79 trans am, 95 trans am, 06 scion tc, and this car is way sportier than any of those. I absolutely love stomping on the peddle when some gear head jock in a crappy 90 something mustang or trust fund punk in his BMW tries to pass me off the light and cut me off in my little economy box. The look on their faces when I am suddenly rocketing past them as the lanes merge. Worth every penny.
Best thing: F#%& big oil! No more gas. EVER!