Hi I was a little surprised by your post because I have flown both types (currently A319) and from the destinations I assume you are flying charter loads eg heavy.
I liked the A320 when I flew it with a good load I would say it compared with the 757.
That however, was 5 years ago and having returned to the Airbus 319 I find it quite a handful in gusty conditions especially when lightly loaded.
Both types have their merits but in terms of feedback and fun I prefer the 757.
Regards Bigpants