Downsides:<p>Search - How do you grep or Ctrl-F your notebook to find out that one command you ran three weeks ago to fix your dev environment?<p>Copy&#x2F;Paste - If I ask you for a copy of your notes, you have to retype it out. I can yank and paste into my e-mail client.<p>In addition, I have to quibble with expandability. Yes, I can buy additional notebooks, but I have finite desk and drawer space. Moreover, the cost of searching increases nonlinearly as the number of notebooks increases. Meanwile, grep runs approximately as quickly on 1kb of notes as it does on 100kb of notes.