On solo rides with a 42-52 when I'm not doing something stupid like intervals, the 52 is rarely used. But on group rides and above threshold efforts, the 52 gets used a lot. I just recently put a 53-39 on my Ironman and the 53 gets more action than the 52 it replaced because the 39 leads to cross chaining more often than the 42. 11 tooth cogs are noisy and I'm glad they are easy to avoid on my C&V rides.