I've bought these 3 years in a row - they're pretty good (as evidenced by the fact that I keep coming back!)
I am pretty rough & ready with my diary- it comes everywhere with me, so I do find that they don't last the whole year, tend to break or come away towards the end. The other issue is that narrow pens slip out, so you really need a thick diameter pen with a shirt hook for most secure results, the ones on the website here (while absolutely beautiful) tended to slip out.