Hi Tom,
I am currently doing my PPL with Flight Academy Barton in their PA28, its an absolute pleasure to learn to fly with them, as they are so friendly and helpful. Their Cessna 172 is potentially one of the newest and nicest aircraft at Barton, as it has a full glass cockpit and the aircraft is also very new. All the instructors are very friendly, I am so glad I chose to fly with them as their fleet of aircraft are just formidable!
Hope you do enjoy your trial flight in the c172 and hope to see you down at Barton one day if you choose to fly there. And also the grass runways aren't as bad as you think, its not even that bumpy to be honest! If you can land at Barton, you can land anywhere as the runways are fairly short!
Regards
Nick