I just installed the Sep 25 update for FTM2012 and decided to see if it had changed it's performance since my last use, abt a year ago. I have been using 2010 since it was faster merging, even though it would shut down when system memory usage got near 3.4 GB (I have 16GBs). Several times a day.
I imported my 28 GB backup file from 2010 into 2012; abt 2 hrs!
Upgraded to tree to 2012 format and continued to add 1940 Census data; which, I had been doing for 2 months with 2010.
To my GLEE, the performance was now similar to 2010s!!!! And, no more memory shutdowns. FTM 2012 is still not perfect in fast merging, but acceptable for a large tree: 31000 people.
Well, I posted too soon. After about two hours, it shut down. Still it is way better.