Just an update for 2015:
I've recently been trying some very low resolution copies of some photos that I took back in March of this year, since trying to synth all of the original photos at their native res always runs out of memory during scene reconstruction.
I had previously uploaded the originals in smaller consecutive sequences, since there were so many images at the location.
I also later tried uploading the photos in interpolated sequences to try to cover the entire environment (or logical segments of it) but thin the coverage to avoid running out of memory.
But recently I just wanted to see if I could get all of the camera positions in one synth, so I put 512px wide thumbnails of all 2,707 of the photos from my Wednesday shoot into one synth, 512px wide thumbnails of all 3,279 of the photos from my Saturday shoot into a second synth, and all 5,986 thumbnails from both days combined into a third synth.