Unfortunatelly there is no ideal 159 petrol engine. I used to have diesel 1.9 16V saloon remapped to 190BHP/380Nm, but after 6 years I needed change to estate(family expansion), and wanted petrol this time. I did testdrive of 3.2JTS, but that dissappointed with performance, fuel consumption and a number of cases read on polish forum with serious engine failure (nice sound though), so went for 1.75TBI.
There is no engine sound at all in TBI - it is very quiet - my wife's Giulietta 1.4TB stock exchaust is wild thing comparing to TBI's. Engine behaves a bit like it was turbo diesel - e.g. it does not rev up that much as some other pertrol (e.g. vs 156 2.5 V6 I had pleasure to drive). It is not too much economical though in terms of fuel consumption as wll. But as others said, still it is nice thing if you do not like diesel and want bit more.
My TBI was remapped to 240BHP/370Nm for RON98 fuel (stock was 210BHP/330Nm), drives even nicer, though for front wheel drive car sometimes it is bit too much now (would prefer if car was RWD or AWD for that engine).
Oil changes every 10-15kkm are must to keep turbo healthy, and use better oil than Selenia Star PE 5W40. There were cases where turbo died at 50-100kkm, but usually when people changed oil every 35kkm. Repair as far as I heard can be sorted out in ~EUR400, though if you go to dealer they will offer you new turbo for more than EUR2000 + replace costs.