Several have said that if you can find the exact same model on the sim as what you buy then it's like an near identical real world experience. Anyway, what I noticed in flying helis on the simulator is that I am able to control the 90-size sips a little bit better than the 50-size birds. Likewise, anything smaller than a 50 has been really hard for me to see.
the 90 size ship is more stable and smoother than a 50 so it feels so nice on the stick, but the 90 is faster and accelerates much quicker, and that is what will get you into trouble,, but if you have been flying for a while then you know what to expect, just take time and learn it's power,, let me tell you> when I went from a 30 size to a 50 size my first thought was "wow, this thing's quick"
good luck !!
Jim