I had the 2D seat about two weeks ago. The cross-over issue during boarding is valid, especially if you are tall. I got stepped on and rolled over. You can live through it.

Another downside is the lack of storage compared to the 2A/B and 2H/J seats. You dont have a seat back pocket in front of you for small items, and you can't stow anything under the seat in front of you. Thus, if you want a laptop/working papers/new book/cd player after take off, you have to get it out of the overhead bins (and put it back before you land).

The upside is that this seat provides you with nearly foolproof isolation from the more colorful passenger behaviors you see described in the buzz.