Interesting observations. One point I would make is that a comparison of start to end of regime is not the best measure of how good it is. We want to compare start to the same date given a different regime. Most places in the world were a lot better off in 1991 than they were in 1919.

The cost of losing liberty or (in the extreme) living under a police state aren't tangible, but they need to be added into the mix.