I fly a 172 with a CD155 engine in a large group. It is a well equiped aircraft and was expensive to acquire, so the hourly costs are not cheap. It is quite heavy and performance low down is nothing special. It requires lengthy warm up and cool down periods. Power setting is done by setting a percentage, so you have to look down and consciously check it. This takes a bit of getting used to as the throttle movement makes setting exact percentages not very intuitive. We run it on car diesel, which is a lot cheaper and with the lower fuel burn the fuel cost to the group is much lower.