Just thought I'd give my initial feelings/thoughts/impressions now that I've owned my 156 for a bit over a month. Remember this is my first Alfa in 25 years, so it should be fairly objective. For the record it's a '99 2.0l twin spark manual.
Well, it looks great.. it's definitely nice having a car that stands out from the standard designs. Still catch myself eyeing it off quite a bit! Feels smooth and very refined, especially for a four cylinder car. Some might say it's a bit muted, but I prefer refined. Feels a bit snoozy to me, but I've just come from a car that does the 0-100 dash in 6 flat. You really need to wring its neck to feel like you're going quick, but having said that I think the quietness and smoothness goes some way to fooling you into thinking it's not as brisk as it is (is it really an 8.6sec 0-100 car as per the stats?). I'm just not used to Swifts and Hyundais keeping up with me I guess, usually they're a distant speck by the time I snag 2nd gear. But I'm loving the economy. Even if I can't keep under 10l/100km (haven't filled up enough to have a good idea of economy yet) it's still better than 15-16l/100. Is it worth doing 98ron fuel, either for economy, performance or general running? Steering is very direct--you point, it goes. Gear shift is nice and easy although it did balk going into 2nd at high revs the other day, but I probably rushed it. Ride is nice if not too compliant over the ever present speed humps. I'm slowing to max 30 even for quite shallow ones. I'm sure I used to do 50-60 without spilling my coffee in my Astra a few years back

The kids love it, especially the hidden rear door handles and boot lock. The boot is quite serviceable, even decent. Interior is nice (I have velour) and seats comfy enough, but I haven't done a long trip yet (without cruise control... sob). Real wood gear knob and steering wheel are kind of different (I like them) but the fake wood fascia is tacky. Did I mention those looks...
On the downside, I'm not loving the thought of maintenance costs, even though I knew it wasn't great (it's far worse than I knew--see a previous thread of mine). The air con sucks. Glad I didn't pay the $50k+ for it new and get a/c like that. The glove box is near useless. The stereo isn't good (I've replaced it). No cup holders *cough*. The brakes squeal annoyingly and embarrassingly, and the brake dust builds up in a week or two on all four alloys. And there's a space saver spare tyre

As you can see the cons have little to do with the driving experience and more with the
quirks character of the Alfa, and I certainly haven't put it through its paces yet (I'll feel somewhat fragile until I get that timing belt done.. ASAP I promise).
I hope this wasn't too random, and that it gives aspiring first-time 156 owners looking at the 2nd hand market an objective glimpse at some pros and cons of owning this great little car.