I'm in the middle of my 1M run, and currently in Quito.
I did MIA-MGA-GUA on friday which went fine, with an airside transfer in MGA, although the CM flight to GUA was delayed.
On Saturday morning I turned up at the airport in GUA for my GUA-SAL-SJO-BOG run on GU, TA and LR. When I went to check in, the check-in person beamed at be: Oh hello. Your flight to SAL is delayed so we have booked you on the earlier TA flight. Very impressive customer service, but you can all appreciate my consternation. In the end it was all solved, and got to BOG on time. Continued to PTY on MM, and then got booted off the overbooked Copa flight to GYE. They rebooked me on the CO flight 2 hours later, but then off course missed the connection in GYE to LIM on VH. I stayed one (long, boring) day in GYE before continuing to LIM. At now in the middle of a LIM-UIO-LIM return on Aces, and next week will go to IQT.

So far though a very good experience. Met a few people on the flights who were also doing the same - 1 from Flyertalk, 3 more not.