Ive owned a 1.6 TS 147 for nine years and covered 91k (bought it new) and I can honestly say the build quality has been as good as any other car I have owned but it hasnt been 100% reliable.
The reason it hasnt has been due to me neglecting servicing. If alfa reccomend the timing belt is changed at 36k or 3 years they really mean it.
They really do drink a litre of oil every 1000 miles and neglect it at your peril.
The body panels are soft as butter and will dent if you stare at them long enough.
Mines had two cam belt failures one at 45k miles and again at 90k its a very expensive way trying to avoid the £300 odd quid it costs to replace it. 1st rebuild cost me £1500 and second time around I put a breakers yard engine in it.
I've had a power steering hose split and the gear linkage went sloppy about 75k
Its still on all its original supension.
Its still on its original discs (pads changed twice)
No electrical faults what so ever.
Its a great cabin and the ride quality is superb
It has the sexiest grill in the world (I'll explain one day)
Its started every morning until this winter (replaced battery at 9 years old)
Its not a vauxhall and its not German
Makes a nice noise which makes me feel good.
The real let down in alfa ownership me is ....
The worse dealer network in the country by a huge margin
Some parts prices are ridiculous.
To sum it up. I wouldnt reccomend an alfa if you dont keep an eye on servicing.
Go for it