I have a 1.9JTD m-jet GT. I also hate diesel engines.
I also have a 2.0TS 916 Spider, I guess they're listed somewhere up there ^^^
Anyway, I do about 13-14k in the GT per year. The TS is just for laughs so its a few at the most as a rule.
The TS needs a cambelt service and variator replacement. Not sure when done what difference it will make.
The TS is 150bhp (allegedly) and again the GT is 150bhp (allegedly and assuming it has not been remapped). The GT probably has more torques than the 916. The GT has 80k on the clock the Spider 100k. According to Wiki the weight of the 916 is 1350–1470 kg, I'm guessing the upper end is the V6 so the TS 2.0 is about 1350kg?
The GT weight is 1395–1485 kg. Is the diesel heavier than the V6? Lets say 1440kg.
The Spider sounds pretty good for a four pot, in fact the best sounding 4 pot I've owned and by a country mile. It does not feel that fast at all to me though, maybe the good service is needed. In fact the previous Rover 25 1.6 I had before the 916 felt quicker from what I remember.
The GT sounds horrific at idle, real taxi like. However once its moving past 20mph it will walk all over my 916. In my hands I'm pretty certain (I'm an average driver at best) I'd beat the 916 easily and every time. Certainly in a drag race and probably on a proper country road.
The 916 is the better car, the one I'll never sell (unless a V6 comes up at the right time).
Part of that is the open roof I'm sure, however even with the roof up, the 916 looks better and always sounds better. It's just a lovely place to be.
The GT was bought because it was practical (hatch) and economical (low tax and mega MPG) relative to the 916. I used the 916 as my daily for the first few months until I purchased the GT (because the TS 916 sold me on Alfa).
The GT is still a pretty good looking hatchback (or coupé).
That's why I'd take the 916 TS over the GT. In your case the 147 is IMO a pretty car but then so is the GT.
Can you live with the clattering diesel racket and good turn of speed vs the 147 4-pot wonderful musical engine (assuming it sounds like the 2.0TS 916)?
You need to try a GT dieseasal and see what you think. The only way to be sure