I bought my first Leuchtturm about a year ago when I found them next to the Moleskines I normally bought. I'd always hated shelling out so much $$$ for a Moleskine that had terrible bleed-through (I'm a mixed media artist who prefers fountain pens for writing). I decided to take a chance on the more inexpensive Leuchtturm.
I opened it up as soon as I got in my car (impatient much?), and have been using them ever since.
THE GOOD:
1) The pages are numbered.
2) There's a fill-it-yourself Table of Contents.
3) It has a Subject/Date line at the top of every page.
4) Includes a few perforated pages at the back, along with some grid pages.
5) Back pocket seems sturdy.
6) Includes label stickers for the spine & cover if you wish to archive it. (I LOVE THIS!!!)
THE BAD:
1) The paper is a bit on the thin side. (It is "ink-proof", that is, no bleed through and doesn't feather with any of the inks I've tried. BUT it is thin, so it will have some show-through on the other side. [very bad on the plain paged Leuchtturm, tolerable on the ruled one.)
2) The elastic isn't as snug as I would like.
THE VERDICT:
I think it's a wonderful notebook for the price, but I personally would steer away from the plain paged Leuchtturm (not very fountain pen friendly for me because of show-through). The binding is much better than the (in)famous Moleskine, and it lies quite flat. The other added functional features make it a great buy, even though the elastic is lacking. I would definitely buy these again (it's cheaper here on Amazon), once I fill up the ones I already own.