Some years ago I tried both the 4-14x44 light stream and Falcon Menace of the same size, both where FFP and both suffered a lot of PX error, the falcon would not group when only 10y of the px setting, a lovely scope if you px for the distance though! it never shifted zero with any amount of adjustment of the mag or px.
So try before you buy!!
FFP scopes do have the benefit of being able to adjust the mag to select the desired depth of field and blur but traded off against being able to fine tune the dot spacing and aimpoints with mag adjustment.
HFT, for people with only 2 buttucks!
VooDoo TwoTwo The next chapter.