Well my own SY-200 has arrived. Liking it a lot so far.
Interesting A/Bing with the FI.
The FI has a broader and more versatile range of core tones and is more synthy in a superb way, that a lot of us are already familiar with. Some ability to tweak on the pedal itself e.g. dry / wet balance is particularly useful for me.
The SY-200 has full ability to edit without recourse to a PC at all , several "usable" tones, flawless tracking / less glitchy than the FI, which for me means that, overall, the SY-200 will be my choice of synth pedal for live use. Part of the explanation for the SY-200's better tracking is that it is polyphonic which allows it to provide cleaner, sharper notes on fast bass lines (not uncommon in the synth bass lines we play) and, for me, is critical for a tight band mix vs a synth bass line that can be somewhat glitchy / "farty" on the FI and which negates the FI's otherwise obvious advantages in terms of core synth tones.