So after 2 years...
You will laugh, but some 4-5 years ago I bought 5 very nice looking walnuts with the idea to push me to learn more of Zbrush and model them. Years passed by but yes! I finally scanned my nuts! :D The models were created for sale. They are on Envato's 3Docean.
the workflow I am using is pretty much based on Bertrand's guide:
http://bertrand-benoit.com/blog/the-poor-mans-guide-to-photogrammetry/I have a 3 light mini studio setup for the photography process. Nikon D90 kit lens 18-105. I shoot raw, process in Lightroom, end up with 2 sets of tiffs for Photoscan - one very contrasty for the build up process and one very flat and non constrasty for the albedo/diffuse texture generation. Export from Photoscan(obj). Zremesh, UVs in Zbrush, project details from high to low poly model, bake displacement, normal, ao. Import retopo/unwrapped high detail model back to the saved photoscan project, generate diffuse keeping the uv mapping generated in Zbrush. Create specular map in Photoshop from diffuse+displacement maps. Import meshes(low and high detail) to 3ds max, scale them to the right size.
Some personal experience comments: I tried solutions from autodesk, both free ones and paid - didn't come to good result in terms of geometry details. Not best results with RealityCapture and crashes. Photoscan is non consistent, I can have 4 fails to align photos and 5th attempt it just aligns them - the main reason I was giving up before until I found I just have to keep trying or align in chunks. Photoscan needs lots of ram, I have a 64gb workstation and some dense point clouds just won't calculate with very high detail setting because not enough ram.
3D architect the software is UVlayout, I didn't have such models yet that require advanced uv work, Zbrush just handles well the meshes I gave it till now.