I haven't played at FT, but I think we can assume the fishiness is equal.
As quester says, the non-monetary factors, are things like software, support and datamine, with the 2 former being a matter of opinion.
When it comes to $, it depends on how many hands a month you play? There are several threads in both Affiliates/Rakeback and Internet Gambling concerning this. I think the concensus is, that for recreational players FT with RB is the better choice.
But I suggest you try looking in these forums, that will greatly help your knowledge, on how to compare the two.
Here you go (hope it works)