OP was a little concerned about the 1L engine being hard worked.
There is merit and value in this question and concern so maybe other factors have to be considered.
In time manufacturing component quality, tolerances, development etc. have meant that 100hp/L is reliably achievable. There is no engine design that has never failed.
What is more important is the trade off between engines with a reliable powerful "buzz box" and an engines that "offer power and torque".
These two factors have long been opposed to each other till we/they introduced variable timing. Fiat's MultiAir technology has certainly changed that balance and allows small high power engines to deliver greater torque than traditional "fixed" engine induction dynamics.
Based on reports in this forum and else where the 1L Sport engine is a competent engine for all drivers.
I do have one reservation and that is in "towing" ability. Generally engine cc = more tow ability. (like for like turbo or no turbo).
I love Italian small cc engines to deliver that x-factor. This has been a stable equation coupled with the Italian factor for many year.
Bottom line is go and test drive (extended if you can get it) and form your own opinion about how the car performs to your driving style and expectations. You will/have to be the final decision maker BASED on your driving requirements (normal, sport, towing, ...)