the 140bhp 1.9 diesel is a very good engine. I have had mine for just on 6 months and have driven about 10k miles so will be having the first 12k service in a couple of weeks. compared to the old 2.4 (not driven the new one) it is about the same on tickover (typical tractor like diesel) but is quieter on driving. the sound is not as good as as the petrol 156's it is more of a "thrum" than the roar you get with petrol but pleasant all the same. there is a turbo lag up to 2k Giri but then the power is fantastic so overtaking is easy. it is fast, i am sure it is faster than the figures that Alfa claim 0-60. The engine in the 1.9 16v GT 150BHP is better and smoother though.
the engine has been totally reilable starting first time and runs as well now or better than when new. gearbox also good. It has not used any oil and delivers 44 mpg around town 50+ mpg on a run average about 48 , so no complaints there. I do a high milage so economy is important and compared to previous petrol cars it does deliver.
suspension is hard but only uncomforatble on deep potholes. I have 17" wheels but would like to compare with 16". not yet grounded the sump on anything to speak of....the same can not be said of the 147 JTD that i had on test drive...bit embarrassed to hand it back...
Insurance for me is £360 with full no claims and no points (yet) from direct line.
Have had a few problems but fewer than the VW passat that i had a few years ago:
airbag light- passenger wiring loom replaced
Paintwork - respray in some areas and polish others - poor production control where the paint has been put on properly it is good, where it hasn't it is c**p - mainly the plastic parts.
trim fixing - replaced
inside edge of tyres wearing - wheeels retracked free
New seatbelt fixing
All of these are typical and other people have had here - see other threads. all were fixed under warranty with no argument and a courtesy car where requested so no complaints about the dealer.
i would say go for it but have a look at the 2.4 as well though. you get a few more extras on those models as well.