K11 or K31?

[u/Aggressive-Many997]

Looking to buy either a k11 or k31. K31 would be a rack grade and k11 a select grade. Need advice on the following:

Unsure of which one to get, for those who have bought a rack grade and or select grade k11 or k31, please chime in and inform me on quality of bore, finish etc.

Thank you!