When we first brought these journals in a few years go, I was intrigued by the sizes, amount of pages per journal, and the variety of paper weights and surface texture.
I'm now on my 3rd 140lb Watercolour journal from this brand and I love using it while on the go. The paper is nice and thick, doesn't buckle easily when doing light/medium washes and illustrative work, and holds up to standard erasing with a kneaded, art gum, or vinyl eraser. They fit perfectly into a purse, tote, or backpack and the clear plastic pocket on the back cover is great for holding the watercolour colour charts I made that go with my travel paint palettes. ^_^
One thing to note: a coworker of mine mentioned (we used to carry them years and years ago before bringing them back, this is the second round of Opus carrying the Hand-Book Journals) - Over time the elastic strap on the outside will slowly lose it's elasticity, most likely a latex-based rubber band that naturally breaks down, becoming brittle as the years pass. Just something to keep in mind - you may need to replace your strap if you don't go through sketchbooks quickly.
Overall though, really lovely book!