You are definitely right that it's more trouble than fresh water, however mollies thrive much better in brackish water and I'm not running a low-end brackish tank, any other suggestions?
To be honest I haven't found this to be true. I have Mollies in freshwater and in brackisha and I don't see any differences in the fish. Both seem to eat, grow and reproduce at the same rate. Of course, that's just my observations. I even move them back and forth with out acclimating them. From what I've read, fish that live in brackish water are used to the salt levels fluctuating.