I'm in a position where I know where you're coming from about pro's and con's of Merc and Alfa ownership.
We have a 98 145 Cloverleaf and a 91 Merc 300D. The Alfa is one of the best feeling cars to drive since my old Mk1 Astra GTE. Whenever it's parked up amongst all the Saxos/Novas/Corsas at Tesco etc, you feel a bit sorry for the owners because they drive bland,soul-less hatches. It makes you feel superior to other small hatches and looks great without adding 150kg of plastic and fibreglass. On the flip side, the 145 has cost us for a new engine (about £1200 including clutch,variator,belts discs and pads)and needs constant monitioring of fluids,wear etc.
You have a girlfriend. She treats you like dirt, belittles you in front of friends and family, won't cook,clean or help round the house, goes out and comes back late often has a smell of 'bloke' about her, never turns up when expected, your family/friends don't like her very much, she drinks too much, is loud and offensive in public, spends all her(and your) cash on expensive clothes and shoes, won't have sex unless it's when SHE wants and when she does, it's explosive,sweaty and adventurous.
You can't explain why, but for all these faults, you still love her.....a bit like our time with the 145!!
The Merc has been the epitomy of German engineering. It's comfortable, reliable, runs on any old sh**e oil, does 45mpg, has THAT badge on the bonnet,has the pre-Chrysler build quality. It cost me £2k to buy in 2004 as it belonged to a mate for 3 years previously who looked after it well. In all that time,it's needed 5 oil and filter changes, new pads and discs all round (£90), exhaust (£110), serpentine belt (£8), glow plugs (£18). Why buy a new-ish Mondeo/Vectra etc when you can run one of these for Fiesta money?
You have a girl friend. All your family like her, your mates think she's a really nice but she's not their type, she has your supper ready when you get in from work,she's quiet and unassuming, when at work she methodically goes about her job with no fuss,she feels guilty if she spends more than £10 on herself in Primark, she hardly ever drinks and will drive you and your pals home without a complaint,rarely goes out and is back early when she does,the house is always clean and tidy, although she will have sex almost whenever you want ,it's pretty ordinary and conventional, she's always there when you need her and doesn't complain if you don't see her all weekend.
Basically,what it's like owning an old Merc. Safe and reliable but wish she'd let her hair down a bit more.
These two cars cover all the bases for me. The Alfa fills the 'Sporty' role and is soooo rewarding to drive. The Merc may be slow and heavy but it wafts along with the minimum of fuss and can sit on the driveway for weeks on end and always starts and runs perfectly.
A great combination of cars!!