Test drive, test drive, and test drive some more. If the salesman doesn’t want to let you go beyond their 2 mile, round the block, drive, then leave and find another place that will. Maybe ask if they have a demo car you can have overnight where you can run some errands or go for a nice long drive to see how you like it.
The seat in my old Civic was decent around town, but a trip out of town, or over rough road, made for some bad times. The seats in my current CX-7 are quite comfortable even on long trips and the car handles bumps a lot better than the Civic as well. Though my Civic just had back and forth lever on it plus a back adjust, the CX-7 has an 8way power adjustable seat. Not sure what’s available on the lower trim models, but my GT has the heated leather seats, and the heated seat does help alleviate some back pain after a hard day at work(they aren’t just for winter).