Meshlab is indeed useful for a lot of things, particularly stitching multiple point clouds together and surface reconstruction of point clouds. Meshmixer isa bit more like ZBrush and Mudbox with its sculpting/smoothing tools (but it's free) and on the model repair side it's useful to get visual indications of where the mesh errors are. ZBrush still does my head in a bit, but in may have to keep learning that, if only for tidying up the texture maps at the end, but for TG this is not a critical step.
You can also export the cameras from Photoscan. Not sure if ZBrush can use these but I think Mudbox can.
The elephant was technically a difficult subject because it's very smooth with large areas of even colour and I had to do a fair bit of editing of the mesh. The tree on the other hand was a lot easier, and has Had no editing of the mesh. erros introduced by the use of an extremely wide angle lens were removed from the point clouds before generating the final mesh.
I'm finding this is meeting a number of people's needs at the uni, and one of the things everyone mentions is"fancy visualisations" of the objects/scenes they want to capture for which TG is pretty good at. Yes, it looks like I can finally get paid to do this stuff at "work"
If you're already using 123D Catch to create objects I'd say that the standard version of Photoscan is a worthwhile investment. We're using Canon 5Ds but that's because we have them. Any camera with a good lens that can save RAW images at 12-18MP will do. The canon S110 for example is used in drones to do stuff like this:
http://m.youtube.com/watch?v=NuZUSe87miY (Software for that was Pix4D, but it's the same principle)
