I can see the appeal of the 2.5 m20 engine!! 171bhp is a good load of poke
The problem nowadays is getting the space and feedom to utilise all that power...171bhp is as useless as 129bhp sitting in a traffic jam on the m25
however, I've been running my 320 touring since march this year and I must say I LOVE IT!!!!
the 2.0 seems to be a bit more rapid at spinning up (compared to the 325's i've driven), and the noise from it past 4000rpm is amazing
Its not a 'lazy car' to drive, as you cant exploit the torque in the same way as a 2.5-so even if you're driving fairly gently, it provides an involving drive.
The fuel consumption of mine is'nt too bad (35mpg on a run, 27ish around town) and can probably be put down to the fact that most 320's have a 4.10 diff fitted.I will hopefully get a taller diff off a 325 fitted at somepoint, to reduce the revs at motorway speeds.
TBH I'm not really too bothered about racing saxo's etc, but I have no problems passing them when needed. 129bhp is plenty in a car weighing 1300kgish
for comparison the new astra is available with a 1.4 16v (giving 80ish BHP) in a car weighing 1725kg
Widge, I know that the 2.0 is flat-topped as opposed to 'hemi'd' but you can argue that the reduction of Alloy present in the 2.5 head is what makes them more 'fragile'... (as for being a 2.5 snob-you're gonna have 2.0 conrods in your 2.7

)
Furthermore, IMO two of the nicest sounding engines in the world are 'flat top'
1930's Harley v twin (also a side valve)
1960's Dodge 440 v8 (flat topped as opposed to the 427 hemi)
and as already said the 2.0 m20 engine in an e30 provides a cheap and viable way into owning a 6pot bmw, yes the fuel consumption isnt great, but neither is it worse than the 2.5