SU-8 is one of the easiest and most used photoresists in microfluidics, and the other photoresists tend to be more poorly understood by the community (generalization). S-1813 is a positive photoresist, so your mask colors will have to be inverted (dark becomes clear, clear becomes dark). Beyond that everything about the process parameters and the developers will be different for the two photoresists. You will want to read the datasheets. Interestingly, positive resists also reflow, at an elevated bake, rectangular cross section channels will become semi-elliptical, so you can take advantage of that for certain applications (valving).