I've had mine for almost two weeks now. So far it's no less or more expensive than say a Polo (which I've 'borrowed' on occasion before). Yeah, insurance is gonna frown on you. But I wasn't gonna settle for a kitchen appliance - I wanted something with a bit of grunt under the hood, so I said what the heck, I'll live with the insurance premium. I was skeptical just like you, considering the mixed reviews. I decided to put the criticism aside and settle for a 147 purely because I wanted something different, something beautiful, and something I could be proud of. I'd like to think that if you look after your Alfa, it'll look after you. And once you're hooked, you'll be saying 'Germans make cars?'.
I'd say I'm in exactly the same position, had the Alfa about 3 weeks now and while it is costing more to run (partly my fault for buying the first one I properly looked at) I'm loving every minute of it.
The positives for me are how it drives, how it looks, the sound of the engine and 'that Alfa feeling'
Negatives: cost, it will depreciate more, cost more on repairs and has a lot less space than the German cars I was looking at buying.
Oh and Alfa's b***** useless thin paint that chips if you look at it funny!
All that said, the pros completely out weigh the cons and I'm still really happy with it (despite having just got back from the petrol station with another £65 bill for fuel!)
I do find myself worrying about what the next bill will be though, will be taking it to Autolusso's Saturday checkup as soon as I can get it booked in and at least get the piece of mind that I know whats going to break!
Getting back to the original post, have a read through the forum. There's a fair few good topics on here about what to look for (like a fool I only signed up after buying!) Once you own it, get in the habit of checking the oil every week and keep it topped up!
Insurance wise at 25 mine is pretty good (actually saved about 50 quid over what my 1.6 Bora was costing me.)