I had the same problem A500 or GPA
1,I wanted something fun/put a smile on my face. Both cars were fun to drive but somehow i couldnt stop smiling when i sat in the 500
2,Car that was also unusual. Lots of F500's and Punto's round here but ive yet to see either in Abarth form near me.
3,Would be actually worth something in 3yrs time. The A500 has a lower list price but retains more value over 3yrs
4,More practical than my Spider. The punto wins hands down here ...but im coming from a 2 seater with a small boot so even the A500 has more space than what im used too
5,I want to personalise my car. The wider choice of colours and options made the A500 more appealing
6,Esseesse. If i choose to SS my car its a lot cheaper with the A500
These were the reasons i chose the A500 and im sure its way many more A500 are sold than GPA (so if you want the rarer car choose GPA) but everyone is different so at the end of the day its you who has to live with car , so only you can make that final decision
Hope this helps