Im useing allplan (CAD) software with the gtx but there is no difference between using the intel gpu or gtx.
For example you can check this video (removed link as it no longer works). In the first sequence you'll see my surface book 2 with allplan and the gtx acting. The second is recorded on my desktop pc. The hardware on my desktop is simliuar (i7-3770, 16GB Ram, Quadro K600). As visible the selecting is takeing much longer on the surface book.