Just received my FX100
Connected to Princeton Reverb RI (great amp)
Plugged guitar straight in - for reference
Did the following experiment -
Switched off everything I could - amp/compressor/gate - EVERYTHING !
And found that to get an identical sound to the guitar running direct - you simply have to push the level of the guitar/overall to the max - seems to give the unit a 1:1 ratio.
From there - I was able to start using the FX100 as a 'normal' FX unit - almost like an M13/M9 - and it works well (not great, like my analog main pedal board) - but very well.
As the Princeton is such a great amp - I find that adding an amp sim is not as effective - but what I used is 'Tube Pre' from the Clean section of the amps - this was actually better for using things like OD/Fuzz as it added cab sim and seemed to handle the OD better.
Interesting unit all in all - I'm going to use it mainly when I'm too lazy to carry my main analog board - and this way I don't have to bend down constantly to edit the sounds. - this is the plan anyways - but over all - pleased :-)