Well, what do I know... Sounded like they cracked a bit early in life and RM was nice enough to replace them. Have you had similar experience?
RM Williams are cracking :( Am I all alone? - Page 3
You're not alone. Mine didn't last 2 years either. They were probably 9 months and never worn in bad conditions (rain, snow etc.) only dry in the fall. Mine cracked just like yours - I was SO disappointed. Blunnies next time for me, although I bought an Italian pair last fall.
I wish I had bothered to take mine back in when this happened... gone too long now.
Hope your new pair hold up.