hmm- that's an interesting conversation in itself.
Comes down to two things I think (for me anyway) as they use the same chassis.
FIAT inherently the budget brand, made a career out of smaller capacity motors beefed up by turbocharging/ Alfa, the sporty brand, had a line in V6 24V larger capacity "pedigree" motors. The cars split depending on whether you want engine charisma (Alfa) or balls-out bhp through technical know-how (FIAT).
Secondly, lovely as the GTV is, it never, nearly looks like it might be related to this attached shot
this is a series 3 850 coupe by FIAT and the modern Coupe as we are discussing here, is an amalgam of Italian car details from the past 40 years- "kick-up" rear arches ala Gandini ;QP Series 4/Lamborghini (whatever), the centre clock in the dash; all current Masers and so on.
Every now and again I get very close to buying an 850; I was in e-mail contact with Tony Castle-Miller at Middle Barton about it last year, but you couldn't do ANYTHING in them nowadays, not in this country anyway, whereas the modern Coupe offers real-world useability and 150 mph.
Sorry- this is going a bit off topic! To pull back;
As for reliability; I've owned; a Marea 5 cyl 20v, a Bravo 5cyl 20v HGT, a Coupe 5cyl 20v, a Bravo 5cyl 20v "155 20v HGT" (series 2) and a Coupe 5cyl 20v Turbo.
So five cars with the same engine (Coupe 20VT had turbo, OK...) and the Marea was the best chassis out of the lot and I never had an engine issue with any of them.
that I can remember anyway...!
JimP