There are many, many posts here where people specifically cite inconsistent paper quality as the reason for their dissatisfaction. You might get a great moleskine that behaves well with almost every ink and nib, and the next week buy one that bleeds and feathers with all but one pen and ink combination.
Here's a thread with a scan:
Why people love, and hate, moleskinesTrumpetvine's terrific tutorial, while intended for adapting a moleskine for ink and watercolor sketching (yes, there is a watercolor moleskine, but some may dislike the landscape format, and this tutorial uses hot press rather than cold press paper), allows someone to use their preferred paper with the moleskine cover and binding. I don't have the ambition to do something like this, but I think it's very cool someone out there does!