The 172 is a little harder to land than the 152 if you approach too fast.
It's equally easy if you approach at the correct speed.
I hate to disagree with a fellow float-plane pilot, but ANY aircraft is more difficult to land if flown too fast.
I once had to land off an ILS in a 172 where to help out ATC, I flew the approach at full-throttle and came over the fence at 130mph. It took a long time to slow down. A good job the runway was 13,000' long!
I have often noticed that instructors who are checking me out, often recommend approach speeds that are higher than those in the handbook. So it pays to check the book.