I went from a 159Ti to a Brera.
My Brera gets about 100 times the attention the Ti got and I often get asked if I've come into money
Everyone comments on it & not in a negative way.
Personally I'd have preferred a 3.2 Q4 Ti 159 but as they are so rare used I opted for my Brera.
Basically, I'm more of a Sports Saloon guy but either are excellent.
My only gripe with the Ti spec is Alfa diluted it a lot come MY 2008
If I saw a low mileage original spec 3.2Q4 Ti for sale at a dealers I'd probably jump at it
Reference other engines, the 2.2 with a map is great fun.
The 200 TBi is quick but sterile. Needs a map & exhaust.
Diesels are generally problematic unless you throw money at them to remove the dreaded EGR & DPF.
They can be easily mapped up though if you like that sort of thing (I don't for sure).
Good luck with your choice