That is like having half a baby. Either have it the whole or none at all. ;-) Gimp hasn't reached the level of Photoshop but is good at what it does.
The techies have already shifted and are very happy.
Is'nt it possible to use Adobe P'shop with Crossover office? P'Shop still beats gimp's pants(with due respect for gimp developers)
Maybe if your techies are still wanting to use windows, try to get them hooked by exporting X to their machines via vnc or a windows X server. Maybe then they will explore Linux a bit more and will be convinced to switch.