Fluorocarbon seems to sink faster than Maxima so it is a good choice for wets and nymphs.
I have used both types with good success. For a given strength rating Maxima is stiffer and seems more resistant to abrasion with better knot strength in my opinion.

Last year I started using Stroft leader material and I like it better than both of the above. You need to choose it based on diameter rather than breaking strength.
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