Wow, Your going to get alot of conflicting info i bet on this one.
Reason, Those who start in SW
will say SW
is easier than FW
cause they know nothing about FW
therefor it woudl be harder than SW
is somewhat easier than SW
simply because you have less water conditions to worry about.
What is more fun? Well each is as much as you make out of it.
Same with exciting. Alot will say SW
tanks are better to look at because of their colors and such but I have seen some wonderful looking FW
tanks that would rival any SW