Just upgraded to HEM2 and though I'd try the free part of NoteCaddy, so I turned it on and restarted HEM.
When HEM finally launched again it started producing Caddy notes (said it needed 1.2 million) but after 700-800k it started to grind to a halt and Task manager showed HEM using 5GB of memory. By the time it got to around 1 million HEM was using 6.5GB of memory and starting to strangle other programs. the update bar showed it was processing about 10 notes/second at this point. Also HEM was blinking occasionally and taking almost a minute to respond (and occasionally throwing up Windows not responding dialogs.)
Eventually I had to crash HEM2 and restart and it produced the last 15% of the notes quickly enough with no noticeable side effects yet.