If you haven't shot the film yet I would test out the optimal speed for your equipment. Shoot a typical scene with a fair amount of shadow and mid tone detail. Meter for the mid tones. Shoot a frame at 50, 64, 80, 100, 125, 160 and develop as recommended by the data sheet. Then make a contact sheet or prints. The amount of shadow detail will be a good guide as to the proper exposure. For Acros I find 50 to 64 works best in most developers. Even at those speeds the negatives look thin, but they print nicely. This is due to the very clear film base.