A few things I've noticed...
Strong Points that people LIKE
1) Fluid Initiative: This makes sense to everyone so far and people like it as it really shows the difference between fast, light weapons and slow, heavy weapons. There are a few issues with it but nothing that can't be worked out. I think someone did a statistical breakdown and (barring weapon tricks) a Speed 4, D6 weapon maxes your DPT overall, so that's a good average.
- Some of the gotcha's people have had trouble with is regarding Push (to remember moving all clock items) and the difference between Recovery (no other Recovery maneuvers during that time) and Strain (you can cast spells but at a health cost).
2) Spell Adaptations: This is a big selling point to a lot of people and after a little while it makes sense. It gives a lot of flexibility in making spellcasters who are different without creating vast lists of different spells. There are some 'common' combinations, but in general people can create some flavorful and functional things here.
I believe for most people the hardest part is really the different combat options. This is true for any game; however, as Arcanis is a new system as well, it just compounds it.
Examples:
Movement: There are a lot of different movements and people forget or don't always get the difference.
Maneuvers: Recovery counting down after the Attack Speed is confusing to some
That's it for now
john