Hi olihar,
on my linux box photoscan is using CPU AND GPU (nVidia GeForce 9600GT) and tiepoint detection and matching is not slower than SIFTGPU. I experienced that photoscan bundle adjustment is much faster than with other SfM packages and the resulting 3D Model is of higher quality. I am using only Photoscan standard edition, which works fine for me.
I would like to ask where you found the information, that photoscan uses SIFT and / or SURF feature detection?
kind regards
thomas