It is a great car, looks nice and drives great too. Depending on the age and maintenance status of the car, one of the engine mounts located on the driver side wears off fairly early and needs to be replaced. Many old civic reborn have a leaking power steering pump. If you drive on broken rough roads, the suspension wears off much earlier compared to a corolla and OEM genuine suspension parts are very expensive so many people go for scrapyard or aftermarket new parts, which in most cases have a much shorter life and poorer quality compared to honda genuine.
Talking about negatives coming from a 2012 Corolla, you will notice greater road and ambient noise, stiffer suspension, lower ground clearance, and slightly less trunk space. Depending on how your driving style is, stiffer and lower suspension may also be taken as positives.
The mileage varies greatly depending on driving style. Car is great at highway speeds. RPM is around 2.2K at 120kph and fuel average goes around 15L/km or even higher. However, in stop and go traffic, I think the average is around 8-9L/km.