quality is fractal; good, smooth acid-free paper that can take a wide variety of inks without smearing, discoloring, or bleeding through -- well constructed and durable.
Moleskine notebooks are mediocre in paper quality, though, and not very consistent. You'll see variations based on which of their Chinese suppliers manufactured a particular notebook, but bleed through and feathering are generally sub par for the price.
They're nice and easy to find though, and the form factor's lovely.
Except moleskin are not quality. I bought one (was a fool once), it's not better or worse than normal 80g paper. I draw with pencil A LOT (as my username would suggest), and write a lot and take notes all the time - all on paper. Regular spiral bound notebook is all one needs for effective usage. Everything else is posing.
In my experience, Moleskine notebooks are better as notebooks than the usual alternatives. That's not because of build quality, though - it's more because of the design. Unfortunately, the surcharge for that usability is too much for me.
For a heavy note-taker, regular notebooks are probably better. For drawing, I would look at specialized notebooks. But don't dismiss valuing usability in intermittently used products as mere posing.
